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1.
Andrea M. Quiroga Federico J. Berli Daniela Moreno Juan B. Cavagnaro Rubén Bottini 《Journal of Plant Growth Regulation》2009,28(1):28-35
In many cultivars of Vitis vinifera periods of mild water stress during ripening are thought to increase grape quality for winemaking, even though yields may
be negatively affected. Because abscisic acid (ABA) is involved in the signaling of water stress in plants, we examine the
effects of the ABA signal being given without the concomitant water stress. ABA at 250 mg l−1 was sprayed weekly or biweekly from bud-burst until harvest onto the leaves of vineyard-grown plants of cv. Cabernet Sauvignon.
For ABA-treated plants berry yield per bunch and per plant was significantly increased (1.5- to 2.0-fold) across three consecutive
harvests (2005 through 2007). Number of berries per bunch and per plant was the primary basis for the significant crop increases,
although bunches per plant also tended to increase (1.1- to 1.3-fold) across all three harvests. Other parameters assessed
included number of internodes, shoot length, leaf area, leaf water potential at midday, photosynthesis, and stomatal conductance.
These parameters showed no significant change with ABA treatment, although shoot length tended to be reduced, as was leaf
area relative to control plants. The significantly increased fruit yields were thus accomplished without accompanying increases
in leaf photosynthesis and leaf areas. Juice at harvest had equal levels of sugars (Brix) and somewhat higher levels of anthocyanins
and total polyphenols relative to control values. The two latter trends continued for the resultant wine across two vintage
years. In conclusion, three seasons of experimental trials have demonstrated that ABA application can significantly enhance
yield per plant in the field-grown grape (cv. Cabernet Sauvignon) by favoring increased berry set without diminishing the
quality of the fruit for winemaking use. 相似文献
2.
Claudia Travaglia Ana C. Cohen Herminda Reinoso Carlos Castillo Rubén Bottini 《Journal of Plant Growth Regulation》2007,26(3):285-289
This work investigates the effects of abscisic acid (ABA) on physiologic parameters related to yield in wheat (Triticum aestivum) grown under field conditions with water restriction ranging between 45.7% and 49.5% of field capacity during anthesis and
postanthesis. ABA (300 mg L−1) was sprayed onto the plants at the beginning of shoot lengthening which significantly promoted leaf area and higher concentrations
of chlorophylls and carotenoids in flag leaf at anthesis. ABA also increased soluble carbohydrates in shoots at anthesis,
which were then re-exported to the grains at maturity. This correlated with a yield increase that was achieved by a higher
number and weight of grains per spike, but protein content was not significantly affected. 相似文献
3.
土壤干旱条件下氮素营养对玉米内源激素含量影响 总被引:8,自引:6,他引:8
在田间持水量分别保持于35%、55%和75%±5%的土壤水分条件下,利用盆栽实验研究了土壤干旱和氮素营养对玉米内源激素和气孔导度的影响.结果表明,土壤干旱下氮素营养明显降低了玉米根系木质部汁液ABA浓度,而正常供水下施氮处理间则无显著差异(施氮处理仍较低),同时测定的叶片ABA浓度则呈相反的变化趋势,表现为干旱下施氮处理要高于不施氮处理;施氮处理木质部汁液中ZRs浓度应低于相应的不施氮处理,在调控气孔行为方面并未表现拮抗ABA作用;3种土壤水分条件下,施氮玉米叶片的气孔导度均高于不施氮处理,与木质部汁液ABA浓度呈负相关,说明施氮处理较低的根源ABA浓度是导致其气孔导度较大的主要原因. 相似文献
4.
Masoomeh Etehadnia Doug R. Waterer Karen K. Tanino 《Journal of Plant Growth Regulation》2008,27(4):331-341
The phytohormone abscisic acid (ABA) has been proposed to act as a mediator in plant responses to a range of stresses, including
salt stress. Most studies of ABA response apply ABA as a single dose. This may not resemble the prolonged increasing endogenous
ABA levels that can occur in association with slowly increasing salinity stresses in nature or field situations. Salt stress
response based on method of ABA application was examined in four potato genotypes of varying salt stress resistance: the sensitive
ABA-deficient mutant and its normal sibling, a resistant genotype line 9506, and commercial cultivar ‘Norland’ of moderate
resistance. ABA was applied by root drench at 0, 50, 75, or 100 μM concentrations through a single dose, or by slowly increasing
multiple ABA doses in a sand-based growing system under greenhouse conditions. Salt tolerance was then evaluated after 2 weeks
of exposure to 150–180 mM NaCl stress. The method of ABA application had a marked effect on the responses to salt stress.
Plant responses to the method of ABA application were differentiated according to (1) growth rate, (2) root water content,
and (3) apparent shoot growth response. Under a single dose, growth rate increased in all genotypes under salt stress, whereas
slowly increasing multiple ABA applications generally maintained stable growth rates except in the ABA-deficient mutant where
there was an upward growth trend. Percent root water content was elevated only under slowly increasing multiple ABA doses
in two genotypes, whereas none of the single-dose treatments induced any change. The single ABA dose enhanced vertical growth,
whereas the slowly increasing multiple ABA dose applications enhanced lateral shoot growth. Because exogenous application
is still an artificial system, endogenous ABA was supplied through grafting of ABA-deficient mutant scions onto rootstocks
with known elevated ABA levels. Multiple exogenous ABA applications as low as 50 μM elicited similar shoot water content responses
as grafting treatments without ABA application in the mutant genotype but had no effect on the ABA normal sibling. Shoot dry
weight was significantly increased through grafting over all exogenous ABA treatments. Our study further indicates that the
method of ABA application regime in itself can alter plant responses under salt stress and that certain application regimes
may reflect responses to elevated endogenous levels of ABA. 相似文献
5.
Stomatal Responses of Pearl Millet (Pennisetum americanum (L.) Leeke) Genotypes, in Relation to Abscisic Acid and Water Stress 总被引:1,自引:0,他引:1
HENSON I. E.; MAHALAKSHMI V.; BIDINGER F. R.; ALAGARSWAMY G. 《Journal of experimental botany》1981,32(6):1211-1221
Stomatal responses to water stress and to applied (±)-abscisicacid (ABA) were examined in genotypes of pearl millet (Pennisetumamericanum (L.) Leeke) known to differ in amounts of endogenousABA accumulating during drought. In both a pot and a field experiment,Serere 39, a genotype with a high capacity to accumulate ABA,showed a higher stomatal sensitivity to water stress than didthe low ABA accumulator, BJ 104. In the fieldexperiment, a third genotype, B282, accumulating least amountsof ABA, also had the lowest stomatal sensitivity to water stress. There were no significant differences between these genotypesin stomatal response to applied (±)-ABA, or in the relationshipsbetween leaf conductance and levels of endogenous ABA. It isconcluded that the differences in accumulation of endogenousABA by these genotypes of pearl millet are of functional significance,and that endogenous ABA generated during a water stress whichdevelops over days or weeks mediates stomatal responses to suchstress. 相似文献
6.
It has been suggested that abscisic acid (ABA) regulates a centralized response of plants to low soil resource availability that is characterized by decreased shoot growth relative to root growth, decreased photosynthesis and stomatal conductance, and decreased plant growth rate. The hypothesis was tested that an ABA-deficient mutant of tomato (flacca; flc) would not exhibit the same pattern of down-regulation of photosynthesis, conductance, leaf area and growth, as well as increased root/shoot partitioning, as its near isogenic wild-type in response to nitrogen or water deficiency, or at least not exhibit these responses to the same degree. Plants were grown from seed in acid-washed sand and exposed to control, nutrient stress, or water stress treatments. Additionally, exogenous ABA was sprayed onto the leaves of a separate group of flc individuals in each treatment. Growth analysis, based on data from frequent harvests of a few individuals, was used to assess the growth and partitioning responses of plants, and gas exchange characteristics were measured on plants throughout the experiment to examine the response of photosynthesis and stomatal conductance. Differences in growth, partitioning and gas exchange variables were found between flc and wild-type individuals, and both nutrient and water treatments caused significant reductions in relative growth rate (RGR) and changes in biomass partitioning. Only the nutrient treatment caused significant reductions in photosynthetic rates. However, flc and wild-type plants responded identically to nutrient and water stress for all but one of the variables measured. The exception was that flc showed a greater decrease in the relative change in leaf area per unit increase of plant biomass (an estimate of the dynamics of leaf area ratio) in response to nutrient stress—a result that is opposite to that predicted by the centralized stress response model. Furthermore, addition of exogenous ABA to flc did not significantly alter any of the responses to nutrient and water stress that we examined. Although it was clear that ABA regulated short-term stomatal responses, we found no evidence to support a pivotal role for ABA, at least absolute amounts of ABA, in regulating a centralized whole-plant response to low soil resource availability. 相似文献
7.
Jalel Mahouachi Rosa Argamasilla Aurelio Gómez-Cadenas 《Journal of Plant Growth Regulation》2012,31(1):1-10
The effects of exogenous foliar glycine betaine (GB) and abscisic acid (ABA) on papaya responses to water stress were investigated
under distinct water regimes. Papaya seedlings (Carica papaya L. cultivar “BH-65”) were pretreated with GB or ABA and subsequently subjected to consecutive periods of drought, rehydration,
and a second period of drought conditions. Results indicated that water stress induced ABA, jasmonic acid (JA), and proline
accumulation but did not modify malondialdehyde (MDA) concentration. In addition, water deprivation reduced photosynthetic
rate, stomatal conductance, relative water content (RWC), leaf fresh weight, and increased leaf abscission. GB applied prior
to drought imposition decreased the impact of water stress on ABA, JA, proline accumulation, leaf water status, growth, and
photosynthetic performance. However, ABA-pretreated plants did not show alteration of most of these parameters under water
stress conditions when compared with non-pretreated plants except a clear induction of JA accumulation. Taken together, the
data suggest that GB may modulate ABA, JA, and proline accumulation through the control of stomatal movement and the high
availability of compatible solutes, leading to improvement of leaf water status, growth, and photosynthetic machinery function.
In contrast, exogenous ABA did not stimulate papaya physiological responses under drought, but interestingly ABA in combination
with drought could induce progressive JA synthesis, unlike drought alone, which induces a transitory JA increase and may trigger
endogenous ABA accumulation. The data also suggest that irrespective of the pretreatments, papaya did not suffer oxidative
damage. 相似文献
8.
Hormonal changes in papaya seedlings subjected to progressive water stress and re-watering 总被引:5,自引:0,他引:5
Changes on abscisic acid (ABA), jasmonic acid (JA) and indole-3-acetic acid (IAA) levels were investigated in papaya seedlings
(Carica papaya L.) cv. “Baixinho de Santa Amalia” under progressive water stress and subsequent rehydration. Also, the behaviour of leaf
gas exchange and leaf growth was determined under stress condition. The results indicated that ABA and JA differ in their
pattern of change under water stress. ABA continuously increased in leaves and roots during the whole period of stress whereas
JA showed a sharp increase and a later decrease in both organs. Re-watering reduced rapidly (24 h) leaf and root ABA to control
levels whereas the influence on JA levels could not be assessed. Drought and recovery did not alter IAA levels in leaf and
root tissues of papaya seedlings. In addition, water stress reduced stomatal conductance, photosynthetic rate, transpiration
rate, the percentage of attached leaves and leaf growth. Rehydration reverted in few days the effects of stress on leaf growth
and gas exchange parameters. Overall, the data suggest that ABA could be involved in the induction of several progressive
responses such as the induction of stomatal closure and leaf abscission to reduce papaya water loss. In addition, the pattern
of accumulation of JA is compatible with a triggering signal upstream ABA. The unaltered levels of IAA could suggest a certain
adaptive ability of papaya to maintain active physiological processes under progressive drought stress. 相似文献
9.
M. ��ngeles Forner-Giner Juan Rodr��guez-Gamir Eduardo Primo-Millo Domingo J. Iglesias 《Journal of Plant Growth Regulation》2011,30(3):353-366
In this work we investigated the function of abscisic acid (ABA) as a long-distance chemical signal communicating water shortage
from the root to the shoot in citrus plants. Experiments indicated that stomatal conductance, transpiration rates, and leaf
water potential decline progressively with drought. ABA content in roots, leaves, and xylem sap was also increased by the
drought stress treatment three- to sevenfold. The addition of norflurazon, an inhibitor of ABA biosynthesis, significantly
decreased the intensity of the responses and reduced ABA content in roots and xylem fluid, but not in leaves. Polyethylene
glycol (PEG)-induced osmotic stress caused similar effects and, in general, was counteracted only by norflurazon at the lowest
concentration (10%). Partial defoliation was able to diminish only leaf ABA content (22.5%) at the highest PEG concentration
(30%), probably through a reduction of the active sites of biosynthesis. At least under moderate drought (3–6 days without
irrigation), mechanisms other than leaf ABA concentration were required to explain stomatal closure in response to limited
soil water supply. Measurements of xylem sap pH revealed a progressive alkalinization through the drought condition (6.4 vs.
7.1), that was not counteracted with the addition of norflurazon. Moreover, in vitro treatment of detached leaves with buffers
iso-osmotically adjusted at pH 7.1 significantly decreased stomatal conductance (more than 30%) as much as 70% when supplemented
with ABA. Taken together, our results suggest that increased pH generated in drought-stressed roots is transmitted by the
xylem sap to the leaves, triggering reductions in shoot water loss. The parallel rise in ABA concentration may act synergistically
with pH alkalinization in xylem sap, with an initial response generated from the roots and further promotion by the stressed
leaves. 相似文献
10.
Foliar sprays with ABA promote growth of Ilex paraguariensis by alleviating diurnal water stress 总被引:1,自引:0,他引:1
Stomatal closure, relative water content (RWC) and vegetative growth were monitored in Ilex paraguariensis plants grown under well-watered conditions with a photosynthetic photon flux density (PPFD) varying from 100% to 1.5%, and sprayed weekly with either distilled water (control) or 1.89 mM abscisic acid (ABA). ABA treatments caused stomatal closure, ranging from 62% to 73%. These treatments also increased RWC in the early evening from 82% to 92% and 88% to 94% in mature and immature leaves, respectively. Such alleviation of the water stress was correlated with increases in leaf area, leaf dry weight (DW), shoot length and shoot DW. On day 35 from the beginning of the experiment, the increases in DW of both leaves and shoots were 1.5-fold at the 1.5% PPFD and 3-fold (for leaves) and 4.5-fold (for shoots) under 100% PPFD. In water-sprayed control plants grown under 1.5% PPFD shoot length also increased significantly, although these shoots contained more ABA (assessed by capillary gas chromatography–mass spectrometry) than those of plants grown under 100% PPFD. These results show that ABA sprayed on to leaves promotes growth in I. paraguariensis plants by alleviating diurnal water stress. 相似文献
11.
Growth response of barley and tomato to nitrogen stress and its control by abscisic acid,water relations and photosynthesis 总被引:14,自引:0,他引:14
Barley (Hordeum vulgare L.) and tomato Lycopersicon esculentum Mill.) were grown hydroponically and examined 2, 5, and 10 d after being deprived of nitrogen (N) supply. Leaf elongation rate declined in both species in response to N stress before there was any reduction in rate of dryweight accumulation. Changes in water transport to the shoot could not explain reduced leaf elongation in tomato because leaf water content and water potential were unaffected by N stress at the time leaf elongation began to decline. Tomato maintained its shoot water status in N-stressed plants, despite reduced water absorption per gram root, because the decline in root hydraulic conductance with N stress was matched by a decline in stomatal conductance. In barley the decline in leaf elongation coincided with a small (8%) decline in water content per unit area of young leaves; this decline occurred because root hydraulic conductance was reduced more strongly by N stress than was stomatal conductance. Nitrogen stress caused a rapid decline in tissue NO
3
-
pools and in NO
3
-
flux to the xylem, particularly in tomato which had smaller tissue NO
3
-
reserves. Even in barley, tissue NO
3
-
reserves were too small and were mobilized too slowly (60% in 2 d) to support maximal growth for more than a few hours. Organic N mobilized from old leaves provided an additional N source to support continued growth of N-stressed plants. Abscisic acid (ABA) levels increased in leaves of both species within 2 d in response to N stress. Addition of ABA to roots caused an increase in volume of xylem exudate but had no effect upon NO
3
-
flux to the xylem. After leaf-elongation rate had been reduced by N stress, photosynthesis declined in both barley and tomato. This decline was associated with increased leaf ABA content, reduced stomatal conductance and a decrease in organic N content. We suggest that N stress reduces growth by several mechanisms operating on different time scales: (1) increased leaf ABA content causing reduced cell-wall extensibility and leaf elongation and (2) a more gradual decline in photosynthesis caused by ABA-induced stomatal closure and by a decrease in leaf organic N.Abbreviation and symbols ABA
abscisic acid
- ci
leaf internal CO2 concentration
- Lp
root hydraulic conductance 相似文献
12.
Involvement of root ABA and hydraulic conductivity in the control of water relations in wheat plants exposed to increased evaporative demand 总被引:2,自引:0,他引:2
We studied the possible involvement of ABA in the control of water relations under conditions of increased evaporative demand.
Warming the air by 3°C increased stomatal conductance and raised transpiration rates of hydroponically grown Triticum durum plants while bringing about a temporary loss of relative water content (RWC) and immediate cessation of leaf extension. However,
both RWC and extension growth recovered within 30 min although transpiration remained high. The restoration of leaf hydration
and growth were enabled by increased root hydraulic conductivity after increasing the air temperature. The use of mercuric
chloride (an inhibitor of water channels) to interfere with the rise on root hydraulic conductivity hindered the restoration
of extension growth. Air warming increased ABA content in roots and decreased it in shoots. We propose this redistribution
of ABA in favour of the roots which increased the root hydraulic conductivity sufficiently to permit rapid recovery of shoot
hydration and leaf elongation rates without the involvement of stomatal closure. This proposal is based on known ability of
ABA to increase hydraulic conductivity confirmed in these experiments by measuring the effect of exogenous ABA on osmotically
driven flow of xylem sap from the roots. Accumulation of root ABA was mainly the outcome of increased export from the shoots.
When phloem transport in air-warmed plants was inhibited by cooling the shoot base this prevented ABA enrichment of the roots
and favoured an accumulation of ABA in the shoot. As a consequence, stomata closed. 相似文献
13.
以滇润楠一年生实生苗为试验材料,研究在良好水分条件(土壤含水量为70%~75%田间持水量)、轻度干旱胁迫及重度干旱胁迫处理下(50%~55%和30%~35%田间持水量)进行外源脱落酸(ABA)喷施对其生长及生理特性的影响。结果表明: 干旱胁迫使得滇润楠幼苗叶片的相对含水量、株高和生物量显著下降,净光合速率及叶绿素荧光参数(PSⅡ最大光化学效率,Fv/Fm)有不同程度的下降,而根冠比、膜脂过氧化产物丙二醛(MDA)含量显著增加。外源ABA的喷施可提高干旱胁迫下滇润楠幼苗的适应性,尤其是重度干旱下,外源ABA显著提高了叶片相对含水量21.0%,同时增加了植株株高和生物量的累积,提高了根冠比,为良好水分条件的2.1倍;减少了干旱下膜脂过氧化产物MDA的累积,提高了抗氧化酶过氧化氢酶、超氧化物岐化酶的活性,显著增加了脯氨酸的含量,为良好水分条件的7.7倍。外源ABA的喷施显著缓解了干旱胁迫对植株光合器官的不利影响,减少干旱引起的叶片净光合速率及气孔导度的下降,并且减轻了PSⅡ受到干旱的伤害程度,重度干旱下喷施ABA的植株的Fv/Fm显著高于未喷施ABA的植株。外源ABA的喷施可以减轻干旱对滇润楠植株的伤害,提高其抗旱性。 相似文献
14.
Masoomeh Etehadnia Doug Waterer Hielke De Jong Karen K. Tanino 《Journal of Plant Growth Regulation》2008,27(2):125-140
Tolerance of salt stress in potato (Solanum tuberosum L.) increased when the plants were pre-exposed to low concentrations of salt (salt acclimation). This acclimation was accompanied
by increased levels of abscisic acid (ABA) in the shoot. To further study the role of roots and shoots in this acclimation
process, reciprocal grafts were made between a salt-tolerant (9506) and salt-sensitive ABA(−) mutant and its ABA(+) normal
sibling potato genotype. The grafted plants were acclimated with 75 or 100 mM NaCl for 3 weeks and then exposed to 150–180 mM
NaCl, depending on the salt tolerance of the rootstock. After 2 weeks of exposure to the salt stress, the acclimated and unacclimated
plants were compared for physiologic and morphologic parameters. The response to the salt stress was strongly influenced by
the rootstock. The salt-tolerant 9506 rootstock increased the salt tolerance of scions of both the ABA-deficient mutant and
its ABA(+) sibling. This salt tolerance induced by the rootstock was primarily modulated by salt acclimation and manifested
in the scion via increased plant water content, stem diameter, dry matter accumulation, stomatal conductivity, and osmotic
potential, and is associated with a reduction in leaf necrosis. There was also a pronounced scion effect on the rootstock.
Using 9506 as a scion significantly increased root fresh and dry weights, stem diameter, and root water content of ABA(−)
mutant rootstocks. Specific evidence was found of the role of exogenous ABA in the enhancement of water status in grafted
plants under salt stress beyond that of grafting alone. This was verified by more positive stomatal conductivity and upward
water flow in ABA-treated grafted and nongrafted plants and the absence of upward water flow in nontreated grafted plants
through NMR imaging. Grafting using either salt-tolerant scions or rootstocks with inherently high ABA levels may positively
modify subsequent responses of the plant under salt stress. 相似文献
15.
Adrienn Guóth Dániel Benyó Jolán Csiszár Ágnes Gallé Ferenc Horváth László Cseuz László Erdei Irma Tari 《Acta Physiologiae Plantarum》2010,32(4):719-727
The effects of increasing osmotic stress induced by 100–400 mOsm (−0.976 MPa) polyethylene glycol (PEG 6000) were investigated
in a drought-tolerant (Triticum aestivum L. cv. Mv Emese) and drought-sensitive (cv. GK élet) wheat cultivar at the three-leaf stage. During osmotic stress, the decline
of the water potential (ψ
w) was more significant in the leaves, while the abscisic acid (ABA) levels of the roots increased earlier and remained higher
in the sensitive than in the tolerant variety. There was an increasing gradient of ABA content toward the youngest leaves
in the drought-sensitive GK élet, while more ABA accumulated in the fully developed, older leaves of the tolerant cultivar
Mv Emese. In accordance with the rapid and significant accumulation of ABA, the stomatal conductance decreased earlier in
the tolerant cultivar. The effect of water stress on the PSII photochemistry was pronounced only 1 week after the exposure
to PEG, as indicated by the earlier decrease of the net CO2 fixation, the effective quantum yield (ΦPSII) and the photochemical quenching (q
P) in light-adapted samples of the tolerant variety in 400 mOsm PEG 6000. The stress treatment caused more significant reductions
in these parameters toward the end of the experiment in the sensitive cultivar. In spite of small differences in the photosynthetic
characteristics, the net biomass production was not significantly altered by this osmotic stress. The accumulation of ABA
controlled the distribution of the biomass between the shoot and root systems under osmotic stress, and contributed to the
development of stronger and deeper roots in the drought-sensitive cultivar GK élet. However, the root elongation did not correlate
with the drought sensitivity of these cultivars on the basis of crop yield. 相似文献
16.
Water Relations of Cotton Plants under Nitrogen Deficiency: V. Environmental Control of Abscisic Acid Accumulation and Stomatal Sensitivity to Abscisic Acid 总被引:19,自引:4,他引:15
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Suboptimal N nutrition increased the water potential for stomatal closure in water stressed cotton (Gossypium hirsutum L.) leaves. This increased sensitivity to water stress had two components, increased accumulation of abscisic acid (ABA) and increased apparent stomatal sensitivity to ABA. Low N increased the threshold water potentials for stomatal closure and ABA accumulation by about 4 bars and 2 bars, respectively. Low N also greatly increased stomatal response to low concentrations of exogenous ABA applied to excised leaves through the transpiration stream. In low N leaves, kinetin decreased stomatal response to ABA to the level observed with high N leaves. Kinetin by itself had little effect on stomata, nor did it alter stomatal response to ABA in high N leaves. The results suggest a cytokinin-ABA balance which is altered by suboptimal N nutrition to favor stomatal closure during stress.
Ambient temperature and N nutrition interacted to alter stomatal response to water stress. Stress-induced ABA accumulation and apparent stomatal sensitivity to ABA were independently affected. The effects of each treatment, and their interaction, could be explained as the net result of changes in both accumulation and apparent sensitivity. Although the results document environmental control of stomatal response to ABA, either altered partitioning of ABA between active and inactive pools, or altered sensitivity of the guard cells, could account for the data.
相似文献17.
Does root-sourced ABA have a role in mediating growth and stomatal responses to soil compaction in tomato (Lycopersicon esculentum)? 总被引:1,自引:0,他引:1
B. J. Mulholland A. Hussain C. R. Black I. B. Taylor J. A. Roberts 《Physiologia plantarum》1999,107(3):267-276
Isogenic wild-type (Ailsa Craig) and abscisic acid (ABA)-deficient mutant (flacca) genotypes of tomato were used to examine the role of root-sourced ABA in mediating growth and stomatal responses to compaction. Plants were grown in uniform soil columns providing low to moderate bulk densities (1.1–1.5 g cm?3), or in a split-pot system, which allowed the roots to divide between soils of the same or differing bulk density (1.1/1.5 g cm?3). Root and shoot growth and leaf expansion were reduced when plants were grown in compacted soil (1.5 g cm?3) but leaf water status was not altered. However, stomatal conductance was affected, suggesting that non-hydraulic signal(s) transported in the transpiration stream were responsible for the observed effects. Xylem sap and foliar ABA concentrations increased with bulk density for 10 and 15 days after emergence (DAE), respectively, but were thereafter poorly correlated with the observed growth responses. Growth was reduced to a similar extent in both genotypes in compacted soil (1.5 g cm?3), suggesting that ABA is not centrally involved in mediating growth in this severely limiting ‘critical’ compaction stress treatment. Growth performance in the 1.1/1.5 g cm?3 split-pot treatment of Ailsa Craig was intermediate between the uniform 1.1 and 1.5 g cm?3 treatments, whereas stomatal conductance was comparable to the compacted 1.5 g cm?3 treatment. In contrast, shoot dry weight and leaf area in the split-pot treatment of flacca were similar to the 1.5 g cm?3 treatment, but stomatal conductance was comparable to uncompacted control plants. These results suggest a role for root-sourced ABA in regulating growth and stomatal conductance during ‘sub-critical’ compaction stress, when genotypic differences in response are apparent. The observed genotypic differences are comparable to those previously reported for barley, but occurred at a much lower bulk density, reflecting the greater sensitivity of tomato to compaction. By alleviating the severe growth reductions induced when the entire root system encounters compacted soil, the split-pot approach has important applications for studies of the role of root-sourced signals in compaction-sensitive species such as tomato. 相似文献
18.
QTL analysis of drought-related traits and grain yield in relation to genetic variation for leaf abscisic acid concentration in field-grown maize 总被引:14,自引:2,他引:12
Sanguineti M; Tuberosa R; Landi P; Salvi S; Maccaferri M; Casarini E; Conti S 《Journal of experimental botany》1999,50(337):1289-1297
Abscisic acid (ABA) concentration is a quantitatively inherited trait which
plays a pivotal role in the response of plants to drought stress. A recent
study identified 17 quantitative trait loci (QTLs) controlling bulk-leaf
ABA concentration (L-ABA) in a maize (Zea mays L.)
population of 80 F4 random families tested for two years under droughted
field conditions. Sixteen of the QTL regions influencing L-ABA also
harboured QTLs for one or more of the following traits: stomatal
conductance, a drought sensitivity index, leaf temperature, leaf relative
water content, anthesis-silking interval, and grain yield. The analysis of
the effects of each QTL region on the investigated traits indicated that
L-ABA mainly represented an indicator of the level of drought stress
experienced by the plant at the time of sampling because an increase in
L-ABA was most commonly associated with a decrease in both stomatal
conductance and grain yield as well as an increase in leaf temperature.
Opposite results were observed at one QTL region on chromosome 7 near the
RFLP locus asg8. A model is presented to interpret
these contrasting results in terms of pleiotropic effects.Key
words: Abscisic acid, ABA, drought stress, quantitative trait
locus (QTL), molecular markers, Zea mays.
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19.
Phosphorus nutrition and water deficits in field-grown soybeans 总被引:11,自引:0,他引:11
Phosphorus and water deficits are important limiting factors in agricultural production. A field experiment was carried out
with soybean (Glycine max (L.) Merr.) to determine whether the effect of water stress on field-grown soybean changes with soil P availability, and
whether soil water content affects plant P nutrition. The soil was a Sadler series (fine-silty, mixed, mesic Glossic Fragiudalf)
located at Princeton, Kentucky, USA (37°60′ north, 87°60′ west). The experiment was a factorial with three levels of soil
P availability (4, 19 and 32 mg kg−1, Mehlich III) and two of water (irrigated and non-irrigated). Most of the effects of phosphorus and water stress on soybean
growth were additive, so that, in general, effects of water stress were similar at each P level. Phosphorus deficiency slowed
vegetative development, reduced shoot growth, LAI, P absorption and concentration, seed number, size and yield, and increased
root length density in the surface soil. Water stress accelerated crop maturity, reduced shoot growth, LAI, P absorption and
concentration, seed number, size and yield, and increased root length density. Some interactions between P and water were
observed. Water stress slowed vegetative development only at the lowest P level (P0). The crop had a positive response to
increasing P availability in both situations, with and without irrigation, suggesting that P addition would be justified even
when a dry growing season is likely to occur.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
20.
Effects of abscisic acid (ABA) on grain filling processes in wheat 总被引:13,自引:0,他引:13
The effect of in situ water stress on the endogenous abscisic acid (ABA) content of the endosperm and the in vitro application of ABA on some important yield regulating processes in wheat have been studied. Water stress resulted in a marked increase in the ABA content of the endosperm at the time close to cessation of growth. Application of ABA to the culture medium of detached ears reduced grain weight. Exogenously applied ABA, at the highest concentration (0.1 mM) reduced transport of sucrose into the grains and lowered the starch synthesis ability of intact grains. In vitro sucrose uptake and conversion by isolated grains was stimulated by low ABA concentrations (0.001 mM) in the medium but was inhibited by higher concentrations. ABA application had no effect on sucrose synthase (SS) and uridine diphosphate glucose pyrophosphorylase (UDP-Gppase) activities, whereas adenosine diphosphate glucose pyrophosphorylase (ADP-Gppase), soluble starch synthase (SSS), and granule-bound starch synthase (GBSS) activities were reduced. These results raise the possibility that water stress-induced elevated levels of endogenous ABA contribute to reduced grain growth. 相似文献