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1.
Epinasty promoted by salinity or ethylene is an indicator of salt-sensitivity in tomatoes 总被引:1,自引:0,他引:1
Abstract Six genotypes of tomato (Lycopersicon esculentum Mill.) that differ in their salt-tolerance, were exposed to 200 mol m?3 NaCl for 4 weeks. Seedlings exhibited a marked decline in shoot dry weight accumulation and increased petiolar epinasty after exposure to salinity stress. Ranking accessions on the basis of their relative growth reduction in response to salinity, provided good agreement with the level of epinasty promoted during the salinity treatment. In the absence of salt-stress, leaf epinasty promoted by exogenous ethylene treatment was found to be a positive indicator of the genotypes incipient salt-sensitivity. Endogenous ethylene levels in untreated plants were negatively correlated with ethephon-induced epinasty. Genotypes with normally high endogenous C2H4 levels were less responsive to ethephon treatment and also exhibited greater salt-tolerance than genotypes with low endogenous C2H4 levels. These observations are consistent with the suggestion that a main feature of adaptation in the genotypes examined may involve modulation of their cellular sensitivity to C2H4. The results indicate that leaf epinasty, whether salt- or ethylene-induced, is a sensitive indicator of salt-sensitivity. Ethylene-induced epinasty may, therefore, provide a simple basis upon which to identify and select salt-tolerant plants. 相似文献
2.
Ethylene production in leaf petiole and laminae tissues was stimulated in tomato (Lycopersicon esculentum Mill. cv. UCT5) plants exposed to salinity-stress. At the highest salinity level (250 mM NaCl), rates of ethylene production more than doubled over those observed in non-stressed plants. Correspondingly, petiolar epinasty increased with increasing levels of stress impositions. Both responses were suppressed when either 1 mM -aminooxyacetic acid (AOA), or 100 M Co2+ was simultaneously applied. Co2+, but not AOA, had a pronounced effect on ethylene production resulting from the application of a saturating dose (2 mM) of 1-aminocyclopropane-1-carboxylic acid (ACC), the immediate precursor of ethylene. This result suggests that ethylene production is dependent upon the activity of ethylene forming enzyme (EFE). The magnitude of ethylene stimulation in leaf petioles was related to the salinity level imposed and to the induction of petiole epinasty. In the absence of stress impositions, epinastic responsiveness to ethylene or its precursor, ACC, might provide a simple, indirect criteria to adjudge salt-sensitivity among plants.Research supported by AID contract II, NEB-1070-A-00-2074-00. 相似文献
3.
M. Salim 《Biologia Plantarum》1988,30(4):294-299
Growth and ionic relations were studied in six triticale cultivars of different geographical origins grown in a greenhouse
in nutrient solution with or without the addition of 100 mM NaCl. In 21 d old plants of all the six cultivars growth was little
affected in the salt treatment, whereas in the subsequent three harvests during vegetative phase (after 31, 38 and 45 d),
growth reduction effects of salinity were progressively pronounced. Generally, shoots of all the six cultivars accumulated
relatively more K+ as compared to Na+ or Cl-. Differential accumulation of K+, Na+ and Cl- by various cultivars was coupled
with variable rates of Na+ and Cl- transport from root to shoot which were — to some extent- related to cultivar differences
in growth in saline root media. Chloride content of shoots of the six cultivars was negatively correlated with the relative
growth reduction due to salinity at the four harvests. 相似文献
4.
The activity of antioxidative enzymes in three strawberry cultivars related to salt-stress tolerance
Effects of salt stress on the time course of stomatal behaviors and the activity of antioxidative enzymes such as catalase
(CAT) (EC 1.11.1.6), ascorbate peroxidase (APX) (EC 1.11.1.11), and glutathione reductase (GR) (EC. 1.6.4.2) were studied
in three strawberry cultivars. The responses of the cultivars ‘Camarosa’, ‘Tioga,’ and ‘Chandler’ were compared when they
were irrigated with nutrient solution containing 0, 8.5, 17.0, and 34.0 mM sodium chloride (NaCl) for 30 days. A significant
reduction in stomatal conductance (gs) was seen particularly on the 30th day of the salt treatments only in Camarosa, which is parallel to transpiration rate (E).
CAT activities decreased in all of the salt treatments only in Tioga, while it remained almost unchanged or slightly increased
depending on the period in Camarosa and Chandler. APX activity sharply increased in 17.0 and 8.5-mM NaCl treatments for 30 days
in Camarosa and Tioga, respectively, whereas it linearly increased based on the NaCl treatments in Chandler. On the other
hand, only Camarosa demonstrated a sharp increase in GR activity induced by salinity applied for 30 days. All the data indicated
that control of the stomatal behavior, the higher salt-stress tolerance (LT50) and higher constitutive activity of antioxidant enzymes made Camarosa and Tioga relatively salt-tolerant cultivars. 相似文献
5.
Effects of NaCl stress on proline and cation accumulation in salt sensitive and tolerant turfgrasses
Summary Concentrations of proline, sodium and potassium in shoot tissues of five turfgrass species were measured following exposure
to 170 mM NaCl salinity stress. Salt tolerant ‘Fults’ alkaligrass and ‘Dawson’ red fescue restricted the accumulation of Na-ions to
significatnly low levels compared to the salt sensitive Kentucky bluegrasses (‘Adelphi’ and ‘Ram I’) and ‘Jamestown’ red fescue.
Accumulation of proline began in all species within 24 h of initiation of salt stress but at a more rapid rate and higher
overall concentration for ‘Fults’ alkaligrass. Proline levels were variable and too low in relation to sodium accumulations
to have any significant osmoregulatory role in salt tolerance among all cultivars tested with the possible exception of alkaligrass. 相似文献
6.
Many soybean [Glycine max (L.) Merr.] genotypes that are grown in solution cultures are highly sensitive to the combination of both salinity and inorganic
phosphate (Pi) in the substrate. This effect has been observed on numerous occasions on plants grown in a saline medium that
contained a substantial amount of Ca (i.e., CaCl2/NaCl=0.5 on a molar basis). Because Ca is important in regulating ion transport and membrane permeability, solution culture
experiments were designed to examine the effects of various concentrations of Pi and ratios of CaCl2/NaCl (0 to 0.5 on a molar basis) at a constant osmotic potential (−0.34 MPa) on this adverse interaction. Four soybean cultivars
(‘Lee’, ‘Lee 74’ ‘Clark’ and ‘Clark 63’) were tested.
No adverse salinity x Pi interaction was found on Lee at any ratio and leaf P and Cl were maintained below 300 and 200 mmol
kg−1 dry wt, respectively. Clark, Clark 63 and Lee 74 soybean plants, on the other hand, were severely injured by solution salinity
(−0.34 MPa osmotic potential) when substrate Pi was ≥0.12 mM. Reduced substrate Ca did not intensify the salinity x Pi interaction. On the contrary, the onset of injury was hastened
and more severe with increased CaCl2/NaCl ratios in isotonic solutions. Shoot and root growth rates decreased as injury increased. Leaf P concentrations from
these cultivars grown in saline solutions with 0.12 mM Pi were excessive (>600 mmol kg−1 dry wt) compared with concentrations commonly found in soybean leaf tissue yet they were independent of the severity of injury.
Since leaf Cl increased wiht increased CaCl2/NaCl ratio, we suspect that the severity of foliar injury was related to the combined effects of excessive P and Cl within
the tissue. Lee 74, the only injured cultivar examined that excluded Cl from its leaves, was less sensitive than either Clark
cultivar and its injury was characteristically different. Other ion interactions were reported that may have played a role
in injury susceptibility. 相似文献
7.
Knowledge of stress-responsive proteins is critical for further understanding the molecular mechanisms of stress tolerance.
The objectives of this study were to establish a proteomic map for a perennial grass species, creeping bentgrass (A. stolonifera L.), and to identify differentially expressed, salt-responsive proteins in two cultivars differing in salinity tolerance.
Plants of two cultivars (‘Penncross’ and ‘Penn-A4’) were irrigated daily with water (control) or NaCl solution to induce salinity
stress in a growth chamber. Salinity stress was obtained by adding NaCl solution of 2, 4, 6, and 8 dS m−1 in the soil daily for 2-day intervals at each concentration, and then by watering soil with 10 dS m−1 solution daily for 28 days. For proteomic map, using two-dimensional electrophoresis (2-DE), approximately 420 and 300 protein
spots were detected in leaves and roots, respectively. A total of 148 leaf protein spots and 40 root protein spots were excised
from the 2-DE gels and subjected to mass spectrometry analysis. In total, 106 leaf protein spots and 24 root protein spots
were successfully identified. Leaves had more salt-responsive proteins than roots in both cultivars. The superior salt tolerance
in ‘Penn-A4’, indicated by shoot extension rate, relative water content, and cell membrane stability during the 28-day salinity
stress could be mainly associated with its higher level of vacuolar H+-ATPase in roots and UDP-sulfoquinovose synthase, methionine synthase, and glucan exohydrolase in leaves, as well as increased
accumulation of catalase and glutathione S-transferase in leaves. Our results suggest that salinity tolerance in creeping bentgrass could be in part controlled by an
alteration of ion transport through vacuolar H+-ATPase in roots, maintenance of the functionality and integrity of thylakoid membranes, sustained polyamine biosynthesis,
and by the activation of cell wall loosening proteins and antioxidant defense mechanisms. 相似文献
8.
H. Barker 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(8):1258-1262
Extreme resistance to the potato V potyvirus (PVV) was found in four potato cultivars that contain Ry genes from Solanum stoloniferum. When plants of these cultivars, were inoculated by grafting in shoot tips from PVV-infected tomato plants, necrotic symptoms
developed in some cultivars, although a full hypersensitive reaction was not elicited, while other cultivars were symptomless.
PVV replication was not detected in any of the inoculated plants by ELISA, an infectivity assay of leaf extracts by manual
inoculation to Nicotiana benthamiana indicator plants, or by ‘return grafting’ of shoot tips taken from newly developed shoots of the potato plants to virus-free
indicator plants of tomato. These methods readily detected PVV infection in inoculated plants of cv ‘Flourball’, which does
not contain an Ry gene and is susceptible, and in cvs ‘Maris Piper’ and ‘Dr Macintosh’, which contain gene Nv conditioning a hypersensitive reaction to inoculation. One of the Ry-containing cultivars, ‘Barbara’, has been previously shown to contain two genes that control extreme resistance, defined
as no viral replication in intact plants, to the potyviruses potato viruses Y and A (PVY and PVA). These genes are: Ry
sto
, which conditions resistance to PVY and PVA, and gene Ra, which conditions resistance to PVA only. It was found that in genotypes from a progeny of the cross ‘Barbara’ (Ry
sto
/Ra)בFlourball’ (ry/ra), extreme resistance to PVV segregated with gene Ry
sto
. It is proposed that either gene Ry
sto
conditions broad-spectrum extreme resistance to the distinct potyviruses PVY, PVA, and PVV or that Ry
sto
represents a family of genetically closely linked genes each controlling resistance to a specific virus.
Received: 27 December 1996 / Accepted: 9 June 1997 相似文献
9.
Khaled Sebei Ahmed Debez Wahid Herchi Sadok Boukhchina Habib Kallel 《Journal of Plant Biology》2007,50(4):447-454
Because of its high contents of protein, α-linolenic-rich oil, lignans, and fiber, demand is increasing for flax(Linum usitatissi-mum L.) and flax seed oil as a food source. In this comparative survey, we examined germination and the mobilization of seed
storage products (lipids and soluble proteins) of 3-d-old seedlings from two flax cultivars (N 51 and H 52) challenged with
moderate salinity (up to 200 mM NaCl). At the highest salt concentration, germination appeared to be cultivar-dependent, with
that of ‘N 51’ being less impaired and delayed than in ’H 52’. Sodium chloride inhibited germination via osmotic and toxic
effects, so that seed viability was altered, especially in ‘H 52’. At 200 mM NaCl, lipid mobilization was delayed in the earliest
germination phases. This response was associated with increased proportions of linolenic acid contents in both cultivars and
more linolenic acid-rich molecular species of TAGs. Irrespective of the salt level, soluble protein contents in both cultivars
decreased over time, although a salt-related precocity of protein degradation occurred at 200 mM NaCl. 相似文献
10.
Tolerance to phosphorus stress was studied in Capsicum annuum L. Chile ancho cv. San Luis and bell pepper cv. Jupiter plants.
Plants were fertilized weekly with Long-Ashton nutrient solution (LANS) modified to supply 0, 11, 22, 44, 66, or 88 g(P) m-3 (P0, P11, P22, P44, P66, P88). Phosphorus stress occurred in both cultivars at P0 and P11, with reduced plant growth and
development. At P0, the lowest percentage of total biomass was directed toward reproductive growth. The root/shoot ratio was
greatest at P0, reflecting greater dry matter partitioning to the root system. Growth of ‘San Luis’ was more sensitive to
phosphorus stress than ‘Jupiter’. A greater percentage of total biomass was directed towards reproductive growth in ‘Jupiter’
than ‘San Luis’. Increasing P nutrition elevated leaf tissue P in both cultivars with highest leaf tissue P at P88. There
were no differences in tissue P between P0 and P11 ‘San Luis’ plants, whereas P0 ‘Jupiter’ plants had the lowest tissue P.
Low P-plants generally had the highest tissue N and lowest S, Mn, and B. In both cultivars, gas exchange was lowest at P0,
as indicated by reduced stomatal conductance (gs) and net photosynthetic rate (PN). Internal CO2 concentration and leaf-to-air vapor pressure difference (VPD) were generally highest with P-stressed plants. Phosphorus use
efficiency, as indicated by PN per unit of leaf tissue P concentration (PN/P), was highest at P11. Generally, no P treatments exceeded the gas exchange levels obtained by P44 (full strength LANS)
plants. Both PN and gs declined during reproductive growth in ‘San Luis’, which fruits more rapidly than ‘Jupiter’, whereas no reduction in gas
exchange occurred with ‘Jupiter’.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
11.
Salinity tolerance of normal-fruited and cherry tomato cultivars 总被引:3,自引:0,他引:3
The salinity tolerances (NaCl) of 8 normal-fruited tomato cultivars (Lycopersicon esculentum Mill.) and 4 cherry tomato cultivars (L. esculentum var.cerasiforme) were determined by yield-substrate EC response curves, according to the Mass-Hoffman model, modified by van Genuchten and Hoffman (1984). The same model was used to determine the response curves of leaf dry-weight, stem dry-weight, and plant height against substrate EC and also between yield and leaf concentrations of Cl- and Na ions.According to the salinity-threshold (maximum EC-value without yield reduction) and slope (yield decrease per unit EC increase) parameters, determined from the yield-EC response curves, the cherry tomato cultivars were more salt-tolerant than the normal-fruited ones. However, on the basis of vegetative growth characters-EC response curves, cherry tomato cultivars and normal-fruited ones were similarly affected by NaCl.The ranking of the cultivars by their salinity tolerance, determined from the plots of yield vs. leaf concentrations of Cl- and Na ions, was the same as that evaluated from the yield vs. substrate EC plots. 相似文献
12.
The response of two rice cultivars to external Na/Ca ratio 总被引:1,自引:1,他引:0
The response of the rice cultivars ‘M9’ and ‘M-201’ to nutrient cultures salinated at −0.4 MPa with varying ratios of Na and
Ca was studied. Although the dry matter production of both cultivars was sensitive to the Na/Ca ratio, this correlation was
significant only for M-201. Calcium nutrition was severely affected by the composition of the external solution, and the laminae
exhibited Ca-deficiency symptoms at Na/Ca molar ratios of 78 and 198. Sodium concentration in the shoot decreased as the Na/Ca
ratio in the external solution decreased. Patterns of Na and Cl distribution in the shoot tissues were similar; both ions
were accumulated preferentially in the tillers and older leaves. The Na-induced inhibition of Ca uptake and transport appears
to be more limiting to shoot growth of M9 and M-201 than Na toxicity per se. 相似文献
13.
The responses of five tomato cultivars (L. esculentum Mill) of different degrees of salt tolerance were examined over a range of 0 to 140 mM NaCl applied for 3 and 10 weeks. Judged by both Na and Cl accumulations and maintenance of K, Ca and Mg contents with increasing salinity, the most tolerant cultivars (Pera and GC-72) showed different responses. The greater salt tolerance of cv Pera was associated with a higher Cl and Na accumulation and a lower K content in the shoot than those found in the other cultivars, typical of a halophytic response to salinity. However, the greater salt tolerance of cv GC-72 was associated with a retention of Na and Cl in the root, restriction of their translocation to the shoot and maintenance of potassium selectivity under saline conditions. The salt tolerance mechanisms that operated in the remaining cultivars were similar to that of cv GC-72, as at first they excluded Na and Cl from the shoots, accumulating them in the roots; with longer treatment, the ability to regulate Na and Cl concentrations in the plant was lost only in the most salt sensitive cultivar (Volgogradskij), resulting in a massive influx of both ions into the shoot.The salt sensitivity of some tomato cultivars to salinity could be due to both the toxic effect of Na and Cl ions and nutritional imbalance induced by salinity, as plant growth was inversely correlated with Na and Cl contents and directly correlated with K and Ca contents. This study displays that there is not a single salt tolerance mechanism, since different physiological responses among tomato cultivars have been found. 相似文献
14.
Inhibition of ethylene synthesis in tomato plants subjected to anaerobic root stress 总被引:10,自引:6,他引:4 下载免费PDF全文
Enhanced ethylene production and leaf epinasty are characteristic responses of tomato (Lycopersicon esculentum Mill.) to waterlogging. It has been proposed (Bradford, Yang 1980 Plant Physiol 65: 322-326) that this results from the synthesis of the immediate precursor of ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC), in the waterlogged roots, its export in the transpiration stream to the shoot, and its rapid conversion to ethylene. Inhibitors of the ethylene biosynthetic pathway are available for further testing of this ACC transport hypothesis: aminooxyacetic acid (AOA) or aminoethoxyvinylglycine (AVG) block the synthesis of ACC, whereas CO2+ prevents its conversion to ethylene. AOA and AVG, supplied in the nutrient solution, were found to inhibit the synthesis and export of ACC from anaerobic roots, whereas Co2+ had no effect, as predicted from their respective sites of action. Transport of the inhibitors to the shoot was demonstrated by their ability to block wound ethylene synthesis in excised petioles. All three inhibitors reduced petiolar ethylene production and epinasty in anaerobically stressed tomato plants. With AOA and AVG, this was due to the prevention of ACC import from the roots as well as inhibition of ACC synthesis in the petioles. With Co2+, conversion of both root- and petiole-synthesized ACC to ethylene was blocked. Collectively, these data support the hypothesis that the export of ACC from low O2 roots to the shoot is an important factor in the ethylene physiology of waterlogged tomato plants. 相似文献
15.
The objective of the project was to study salinity-induced effects on essential oil, pigments and salts accumulation in sweet basil (Ocimum basilicum, the cultivar Perrie) in relation to the alteration of plant morphological development and yield production. Hydroponically grown plants were exposed to one of six NaCl concentrations (1, 25, 50, 75, 100 and 130 mM NaCl). Inhibitory effects of salinity on biomass production of the shoot and the root, and area of individual leaves were apparent already under cultivation with 25 mM NaCl. Elevation of salinity from 1 to 100 mM NaCl induced 63% and 61% reductions in fresh and dry herb biomass production, respectively. The stress-induced reduction of foliage biomass sourced mainly from inhibition of leaf area development rather than reduction of internode and leaf number. Cl and Na concentrations in the leaves, stems and roots increased with elevation of NaCl concentration in the cultivation solution. While the extent of Cl accumulation was leaves>stems>roots, Na was largely excluded from the leaves and was preferentially accumulated in roots and the stems, potentially accounting for the moderate sensitivity of the leaf tissue to salinity. Salt stress increased the contents of essential oil and carotenoids in the leaves that may further account for the moderate sensitivity of sweet basil to salinity and suggest a potential for agro-industrial production. A twofold increase in both carotenoid concentration and the percent of essential oil in the fresh tissue was observed by elevation of the salinity from 1 to 130 mM NaCl. Overall, the stress induced increase of the percent of essential oil in the tissue in the salinity range 1–75 mM NaCl was about 50%, and thereby compensated for the similar reduction of biomass production in this salinity range, so that oil production on per plant basis was not reduced by salinity. 相似文献
16.
Krishnamurthy P Ranathunge K Nayak S Schreiber L Mathew MK 《Journal of experimental botany》2011,62(12):4215-4228
Rice is an important crop that is very sensitive to salinity. However, some varieties differ greatly in this feature, making investigations of salinity tolerance mechanisms possible. The cultivar Pokkali is salinity tolerant and is known to have more extensive hydrophobic barriers in its roots than does IR20, a more sensitive cultivar. These barriers located in the root endodermis and exodermis prevent the direct entry of external fluid into the stele. However, it is known that in the case of rice, these barriers are bypassed by most of the Na(+) that enters the shoot. Exposing plants to a moderate stress of 100 mM NaCl resulted in deposition of additional hydrophobic aliphatic suberin in both cultivars. The present study demonstrated that Pokkali roots have a lower permeability to water (measured using a pressure chamber) than those of IR20. Conditioning plants with 100 mM NaCl effectively reduced Na(+) accumulation in the shoot and improved survival of the plants when they were subsequently subjected to a lethal stress of 200 mM NaCl. The Na(+) accumulated during the conditioning period was rapidly released when the plants were returned to the control medium. It has been suggested that the location of the bypass flow is around young lateral roots, the early development of which disrupts the continuity of the endodermal and exodermal Casparian bands. However, in the present study, the observed increase in lateral root densities during stress in both cultivars did not correlate with bypass flow. Overall the data suggest that in rice roots Na(+) bypass flow is reduced by the deposition of apoplastic barriers, leading to improved plant survival under salt stress. 相似文献
17.
Grafting raises the salt tolerance of tomato through limiting the transport of sodium and chloride to the shoot 总被引:22,自引:0,他引:22
Estañ MT Martinez-Rodriguez MM Perez-Alfocea F Flowers TJ Bolarin MC 《Journal of experimental botany》2005,56(412):703-712
With the aim of determining whether grafting could improve salinity tolerance of tomato (Lycopersicon esculentum Mill.), and what characteristics of the rootstock were required to increase the salt tolerance of the shoot, a commercial tomato hybrid (cv. Jaguar) was grafted onto the roots of several tomato genotypes with different potentials to exclude saline ions. The rootstock effect was assessed by growing plants at different NaCl concentrations (0, 25, 50, and 75 mM NaCl) under greenhouse conditions, and by determining the fruit yield and the leaf physiological changes induced by the rootstock after 60 d and 90 d of salt treatment. The grafting process itself did not affect the fruit yield, as non-grafted plants of cv. Jaguar and those grafted onto their own root showed the same yield over time under non-saline conditions. However, grafting raised fruit yield in Jaguar on most rootstocks, although the positive effect induced by the rootstock was lower at 25 mM NaCl than at 50 and 75 mM NaCl. At these higher levels, the plants grafted onto Radja, Pera and the hybrid VolgogradskijxPera increased their yields by approximately 80%, with respect to the Jaguar plants. The tolerance induced by the rootstock in the shoot was related to ionic rather than osmotic stress caused by salinity, as the differential fruit yield responses among graft combinations were mainly related to the different abilities of rootstocks to regulate the transport of saline ions. This was corroborated by the high negative correlation found between fruit yield and the leaf Na(+) or Cl(-) concentrations in salt-treated plants after 90 d of salt treatment. In conclusion, grafting provides an alternative way to enhance salt tolerance, determined as fruit yield, in the tomato, and evidence is reported that the rootstock is able to reduce ionic stress. 相似文献
18.
J. Y. Choi H. J. Kim C. H. Lee J. M. Bae Y. S. Chung J. S. Shin N. I. Hyung 《In vitro cellular & developmental biology. Plant》2001,37(2):274-279
Summary An efficient and simple plant regeneration system via organogenesis from leaf segments of persimmon (Diospyros kaki Thunb.) cultivars ‘Fuyu’ and ‘Nishimurawase’ has been developed. The regeneration capacity was influenced by the culture
vessels, gelling agents, plant growth regulators, and light conditions. Leaf explants taken from in vitro shoots were cultured on a modified Murashige and Skoog medium (MS1/2N), for 16 wk without transfer to fresh medium. Adventious
shoots appeared after 4 and 8 wk in culture of ‘Nishimurawase’ and ‘Fuyu’ tissues, respectively. The culture of leaf explants
in Erlenmeyer flasks with medium containing 4 g l−1 agar enhanced shoot formation in comparison to media with increased agar concentrations. Optimal shoot regeneration was obtained
with 5 mg l−1 (22.8 μM) zeatin and 0.1 mg l−1 (0.05 μM) indole-3-butyric acid (IBA) for ‘Nishimurawase’, and 10 mg l−1 (45.6 μM) zeatin and 0.1 mg l−1 (0.05 μM) IBA for ‘Fuyn’. Shoot regeneration frequencies in both cultivars were 100%, and shoot numbers per explant reached up to
9.2 for ‘Nishimurawase’ and 2.2 for ‘Fuyu’. Dark incubation during the first 4–5 wk was the most effective condition to successfully
influence shoot regeneration in both cultivars. While dark incubation was essential for adventitious shoot formation by ‘Fuyu’,
it was only slightly beneficial to ‘Nishimurawase’. More than 80% of the regenerated shoots rooted within 4 wk on hormone-free
MS1/2N demium after having been dipped for 30 s in 250 mg l−1 (1.1. mM) IBA solution. 相似文献
19.
The effects of water deficit on photochemical parameters and activities of superoxide dismutase, catalase, ascorbate peroxidase
and glutathione reductase were investigated in two olive cultivars differing in drought tolerance — ‘Chemlali’ and ‘Chetoui’.
After 30 days without irrigation, leaf water potential fell to −5.5 MPa that was accompanied by a marked decrease in net photosynthesis
in ‘Chetoui’ olive cultivar. Maximal efficiency of PSII photochemistry (Fv/Fm) decreased slightly in ‘Chemlali’ (28 %) and substantially in ‘Chétoui’ (47 %). Both cultivars showed a similar decline (about
25 %) in the photochemical quenching coefficient, but only the drought-sensitive olive cultivar exhibited an enhancement (31
%) of non-photochemical fluorescence quenching under water deficit conditions. The quantum yield of electron transport decreased
in both olive cultivars. ‘Chemlali’ showed a higher protection against oxidative stress, as judged from the lower levels of
the malondialdehyde production. Catalase activity was higher in ‘Chetoui’. Glutathione reductase activity was increased similarly
in both olive cultivars under water stress. Ascorbate peroxidase activity was enhanced in ‘Chemlali’ under water stress, but
was unaffected in ‘Chetoui’. While, superoxide dismutase activity was inhibited in both cultivars under water stress, but
higher activity was detected in ‘Chemlali’. Thus, the ability to increase ascorbate peroxidase and a higher superoxide dismutase
activity might be an important attribute linked to the drought tolerance in ‘Chemlali’ olive cultivar. 相似文献
20.
Mokhtar Guerfel Alexandros Beis Tasos Zotos Dalenda Boujnah Mokhtar Zarrouk Angelos Patakas 《Acta Physiologiae Plantarum》2009,31(4):825-831
Differences in abscisic acid (ABA) accumulation between two olive cultivars were studied by enzyme-linked immunosorbent assay
in roots and leaves, leaf water potential (Ψl), stomatal conductance (g
s) as well as photosynthetic rate (A) were also determined in well-watered (WW) and water-stressed (WS) plants of two olive
cultivars ‘Chemlali’ and ‘Chetoui’. ‘Chemlali’ was able to maintain higher leaf CO2 assimilation rate and leaf stomatal conductance throughout the drought cycle when compared with ‘Chetoui’. Furthermore, leaf
water potential of ‘Chemlali’ decreased in lower extent than in Chetoui in response to water deficit. Interestingly, significant
differences in water-stress-induced ABA accumulation were observed between the two olive cultivars and reflect the degree
of stress experienced. Chemlali, a drought tolerant cultivar, accumulated lower levels of ABA in their leaves to regulate
stomatal control in response to water stress compared to the drought sensitive olive cultivar ‘Chetoui’ which accumulated
ABA in large amount. 相似文献