共查询到20条相似文献,搜索用时 15 毫秒
1.
Shucai Wang Shin Taketa Masahiko Ichii Langlai Xu Kai Xia Xie Zhou 《Plant Growth Regulation》2003,41(1):41-47
Comparative effects of indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) on lateral root (LR) formation were studied using 2-day-old seedlings of IR8 rice (Oryza sativa L.). Results showed that IBA at all concentrations (0.8–500 nmol/L) increased the number of LRs in the seminal root. However exogenous IAA, failed to increase the number of LRs. On the other hand, both IBA and IAA caused inhibition of seminal root elongation and promotion of LR elongation, but IAA can only reach to the same degree of that of IBA at a more than 20-fold concentration. Exogenous IBA had no effect on endogenous IAA content. We conclude from the results that IBA could act directly as a distinct auxin, promoting LR formation in rice, and that the signal transduction pathway for IBA is at least partially different from that for IAA. 相似文献
2.
Effect of iron plaque outside roots on nutrient uptake by rice (Oryza sativa L.): Phosphorus uptake 总被引:1,自引:0,他引:1
Under anaerobic conditions, ferric hydroxide deposits on the surface of rice roots have been shown to affect the uptake of
some nutrients. In the present experiment, different amount of this iron plaque were induced on the roots of rice (Oryza sativa
L. cv. TZ88-145) by supplying different Fe(OH)3 concentrations in nutrient solutions, and the effect of the iron plaque on phosphorus uptake was investigated. Results showed
that 1) iron plaque adsorbed phosphorus from the growth medium, and that the amount of phosphorus adsorbed by the plaque was
correlated with the amount of plaque; 2) the phosphorus concentration in the shoot increased by up to 72% after 72 h at concentration
of Fe(OH)3 in the nutrient solution from 0 to 30 mg Fe/L, corresponding with amounts of iron plaque from 0.2 to 24.5 mg g-1 (root d. wt); 3) the phosphorus concentration in the shoots of rice with iron plaque was higher than that without iron plaque
though the concentration in the shoot decreased when Fe(OH)3 was added at 50 mg Fe/L producing 28.3 mg g-1 (root d. wt) of plaque; and 4) the phosphorus concentrations in Fe-deficient and Fe-sufficient rice plants with iron plaque
were the same, although phytosiderophores were released from the Fe-deficient roots. The phytosiderophores evidently did not
mobilise phosphorus adsorbed on plaque. The results suggest that iron plaque on rice plant roots might be considered a phosphorus
reservoir.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
3.
4.
S. S. Virmani R. C. Aquino G. S. Khush 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1982,63(4):373-380
Summary Studies conducted at the International Rice Research Institute (IRRI) during 1980 and 1981 have shown up to 73% heterosis, 59% heterobeltiosis and 34% standard heterosis for yield in rice. The latter was estimated in comparison to commercial varieties: IR36 and IR42 (yield 4–5 t/ha in wet season trials and 7–8 t/ha in dry season trials). Generally speaking, absolute yield was lower and extent of standard heterosis was higher in wet season than in dry season with some exception. Yields up to 5.9 t/ha (22% standard heterosis) in the wet season and 10.4 t/ha (34% standard heterosis) in the dry season were obtained. Most of the hybrids performed better in some season while some performed better in both seasons. Hybrids showed better lodging resistance although they were 5–10 cm taller. F1 hybrids had significant positive correlations with the parental traits viz., yield (r = 0.446), tillering (r = 0.746), height (r = 0.810) and flowering (r = 0.843). Selection of parents among elite breeding lines on the basis of their per se yield performance, diverse origin and resistance to insects and diseases should give heterotic combination. Yield advantage of hybrids was due primarily to increase in number of spikelets per unit area even though tiller number was reduced. Grain weight was either the same or slightly higher. High yielding hybrids also showed significant heterosis and heterobeltiosis for total dry matter and harvest index. For commercial utilization of heterosis in rice, effective male sterility and fertility restoration systems are available and up to 45% natural outcrossing on male sterile lines has been observed. Consequently, F1 rice hybrid have been successfully developed and used in China. Prospects of developing hybrid rice varieties elsewhere appear bright especially in countries that have organized seed production, certification and distribution programs and where hybrid seed can be produced at a reasonable cost. 相似文献
5.
6.
Di Dong-Wei Sun Li Zhang Xiaonan Li Guangjie Kronzucker Herbert J. Shi Weiming 《Plant and Soil》2018,432(1-2):373-387
Plant and Soil - Ammonium (NH4+) is an important nitrogen source and is widely used as a fertilizer in agricultural systems. However, excess NH4+ inhibits root growth, and, subsequently, vegetative... 相似文献
7.
BUALUANG FAIYUE MOHAMMED J. AL‐AZZAWI TIMOTHY J. FLOWERS 《Plant, cell & environment》2010,33(5):702-716
Although an apoplastic pathway (the so‐called bypass flow) is implicated in the uptake of Na+ by rice growing in saline conditions, the point of entry of this flow into roots remains to be elucidated. We investigated the role of lateral roots in bypass flow using the tracer trisodium‐8‐hydroxy‐1,3,6‐pyrenetrisulphonic acid (PTS) and the rice cv. IR36. PTS was identified in the vascular tissue of lateral roots using both epifluorescence microscopy and confocal laser scanning microscopy. Cryo‐scanning electron microscopy and epifluorescence microscopy of sections stained with berberine‐aniline blue revealed that the exodermis is absent in the lateral roots. We conclude that PTS can move freely through the cortical layers of lateral roots, enter the stele and be transported to the shoot via the transpiration stream. 相似文献
8.
Allelopathic potential in rice (Oryza sativa L.) germplasm 总被引:10,自引:0,他引:10
9.
Arsenic uptake and accumulation in rice (Oryza sativa L.) irrigated with contaminated water 总被引:1,自引:2,他引:1
Long-term use of arsenic contaminated groundwater to irrigate crops, especially paddy rice (Oryza sativaL.) has resulted in elevated soil arsenic levels in Bangladesh. There is, therefore, concern regarding accumulation of arsenic in rice grown on these soils. A greenhouse pot experiment was conducted to evaluate the impact of arsenic-contaminated irrigation water on the growth and uptake of arsenic into rice grain, husk, straw and root. There were altogether 10 treatments which were a combination of five arsenate irrigation water concentrations (0–8 mg As l–1) and two soil phosphate amendments. Use of arsenate containing irrigation water reduced plant height, decreased rice yield and affected development of root growth. Arsenic concentrations in all plant parts increased with increasing arsenate concentration in irrigation water. However, arsenic concentration in rice grain did not exceed the maximum permissible limit of 1.0 mg As kg–1. Arsenic accumulation in rice straw at very high levels indicates that feeding cattle with such contaminated straw could be a direct threat for their health and also, indirectly, to human health via presumably contaminated bovine meat and milk. Phosphate application neither showed any significant difference in plant growth and development, nor in As concentrations in plant parts. 相似文献
10.
In waterlogged soil, deficiency of oxygen triggers development of aerenchyma in roots which facilitates gas diffusion between roots and the aerial environment. However, in contrast to other monocots, roots of rice (Oryza sativa L.) constitutively form aerenchyma even in aerobic conditions. The formation of cortical aerenchyma in roots is thought to occur by either lysigeny or schizogeny. Schizogenous aerenchyma is developed without cortical cell death. However, lysigenous gas-spaces are formed as a consequence of senescence of specific cells in primary cortex followed by their death due to autolysis. In the last stage of aerenchyma formation, a ‘spoked wheel’ arrangement is observed in the cortical region of root. Ultrastructural studies show that cell death is constitutive and no characteristic cell structural differentiation takes place in the dying cells with respect to surrounding cells. Cell collapse initiation occurs in the center of the cortical tissues which are characterized by shorter with radically enlarged diameter. Then, cell death proceeds by acidification of cytoplasm followed by rupturing of plasma membrane, loss of cellular contents and cell wall degradation, while cells nuclei remain intact. Dying cells releases a signal through symplast which initiates cell death in neighboring cells. During early stages, middle lamella-degenerating enzymes are synthesized in the rough endoplasmic reticulum which are transported through dictyosome and discharged through plasmalemma beneath the cell wall. In rice several features of root aerenchyma formation are analogous to a gene regulated developmental process called programmed cell death (PCD), for instance, specific cortical cell death, obligate production of aerenchyma under environmental stresses and early changes in nuclear structure which includes clumping of chromatin, fragmentation, disruption of nuclear membrane and apparent engulfment by the vacuole. These processes are followed by crenulation of plasma membrane, formation of electron-lucent regions in the cytoplasm, tonoplast disintegration, organellar swelling and disruption, loss of cytoplasmic contents, and collapse of cell. Many processes in lysing cells are structural features of apoptosis, but certain characteristics of apoptosis i.e., pycnosis of the nucleus, plasma membrane blebbing, and apoptotic bodies formation are still lacking and thus classified as non-apoptotic PCD. This review article, describes most recent observations alike to PCD involved in aerenchyma formation and their systematic distributions in rice roots. 相似文献
11.
Effect of iron plaque outside roots on nutrient uptake by rice (Oryza sativa L.). Zinc uptake by Fe-deficient rice 总被引:6,自引:0,他引:6
This solution culture study examined the effect of the deposition of iron plaque on zinc uptake by Fe-deficient rice plants. Different amounts of iron plaque were induced by adding Fe(OH)3 at 0, 10, 20, 30, and 50 mg Fe/L in the nutrient solution. After 24 h of growth, the amount of iron plaque was correlated positively with the Fe(OH)3 addition to the nutrient solution. Increasing iron plaque up to 12.1 g/kg root dry weight increased zinc concentration in shoots by 42% compared to that at 0.16 g/kg root dry weight. Increasing the amount of iron plaque further decreased zinc concentration. When the amounts of iron plaque reached 24.9 g/kg root dry weight, zinc concentration in shoots was lower than that in shoots without iron plaque, implying that the plaque became a barrier for zinc uptake. While rice plants were pre-cultured in –Fe and +Fe nutrient solution in order to produce the Fe-deficient and Fe-sufficient plants and then Fe(OH)3 was added at 20, 30, and 50 mg Fe/L in nutrient solution, zinc concentrations in shoots of Fe-deficient plants were 54, 48, and 43 mg/kg, respectively, in contrast to 32, 35, and 40 mg/kg zinc in shoots of Fe-sufficient rice plants. Furthermore, Fe(OH)3 addition at 20 mg Fe/L and increasing zinc concentration from 0.065 to 0.65 mg Zn/L in nutrient solution increased zinc uptake more in Fe-deficient plants than in Fe-sufficient plant. The results suggested that root exudates of Fe-deficient plants, especially phytosiderophores, could enhance zinc uptake by rice plants with iron plaque up to a particular amount of Fe. 相似文献
12.
13.
Rohit Joshi Alok Shukla S. C. Mani Pramod Kumar 《Physiology and Molecular Biology of Plants》2010,16(1):99-106
The stress of low oxygen concentrations in a waterlogged environment is minimized in some plants that produce aerenchyma, a tissue characterized by prominent intercellular spaces. It is produced by the predictable collapse of root cortex cells, indicating a programmed cell death (PCD) and facilitates gas diffusion between root and the aerial environment. The objective of this study was to characterize the cellular changes take place during aerenchyma formation in root of rice that accompany PCD. Scanning electron microscopy and transmission electron microscopy were used for cellular analysis of roots. Aerenchyma development was observed in both aerobic and flooded conditions. Structural changes in membranes and organelles were examined during development of root cortex cells to compare with previous examples of PCD. There was an initial collapse which started at a specific position in the mid cortex, indicating loss of turgor, and the cytoplasm became more electron dense. These cells were distinct in shape from those located towards the periphery. Mitochondria and endoplasmic reticulum appeared normal at this early stage though the tonoplast lost its integrity. Subsequently it underwent further degeneration while the plasmalemma retracted from the cell wall followed by death of neighboring cells followed a radial path. However, pycnosis of the nucleus, blebbing of plasma membrane and production of apoptotic bodies were not found which in turn indicated nonapoptotic PCD during aerenchyma formation in rice. 相似文献
14.
Inheritance of gel consistency in rice was studied in crossés involving highamylose, low-gelatinizalion temperature parents
with hard, medium, and soft gel consistency. The results of single-grain analysis of parents, F1, F2, B1F1, B2F2, and their reciprocal crosses from a single-season harvest showed that the differences between hard and soft, hard and medium,
and medium and soft gel consistency are under monogenic control and that modifiers affect the expression of the trait. Multiple
alleles at the same locus, hereby designated asgec
a for medium gel consistency andgec
b for soft gel consistency, were recessive to the wild type allele for hard gel consistency andgec
a was dominant overgec
b. The results indicate that selection for desired gel consistency can effectively be done in early segregating generations. 相似文献
15.
Summary The effect of various doses of copper and zinc on their uptake and on the yield of rice were studied. Copper applications
increased copper contents in the plants without effecting the zinc contents. However, zinc applications though increased zinc
contents but markedly decreased the copper contents in the plants. This antagonistic effect of zinc on copper suggests that
zinc applications can reduce rice yield if available copper is marginal in the soils. re]19720628 相似文献
16.
Changes in abscisic acid (ABA) contents in Cd-treated rice (Oryza sativa L.) seedlings of two cultivars were investigated. On treatment with CdCl2, the ABA content rapidly increased in the leaves and roots of Cd-tolerant cultivar (cv. Tainung 67, TNG67) but not in the Cd-sensitive cultivar (cv. Taichung Native 1, TN1). The reduction of transpiration rate of TN1 caused by Cd was less than that of TNG67. Exogenous application of ABA reduced transpiration rate, decreased Cd content, and enhanced Cd tolerance of TN1 seedlings. Exogenous application of the ABA biosynthesis inhibitor, fluridone, reduced ABA accumulation, increased transpiration rate and Cd content, and decreased Cd tolerance of TNG67 seedlings. Fluridone effect on Cd toxicity of TNG67 seedlings was reversed by the application of ABA. The roles of endogenous ABA in Cd tolerance of rice seedlings are discussed and suggested. 相似文献
17.
QTLs for nitrate induced elongation and initiation of lateral roots in rice (Oryza sativa L.) 总被引:1,自引:1,他引:1
To investigate the genetic background of nitrate-induced elongation and initiation of lateral roots in rice (Oryza sativa L.), a doubled haploid (DH) population, derived from a cross between IR64 and Azucena, which showed different responses to local supplied NO3
– in lateral root elongation and initiation, was used in an agar culture experiment with three separated layers. The second agar layer was supplied with 3 mM NO3
– or without NO3
– as two treatments. Average lateral root length, lateral root number and surface area of lateral roots in the second agar layers with and without nitrate, respectively, were measured. The ratio of the parameters from the two treatments were calculated as derived parameters. Seven putative Quantitative trait loci (QTLs) for the 6 lateral root traits in nitrate-deficient and nitrate-supplied layers were detected. These QTLs individually explained about 9% to 15% of the total phenotypic variations in the traits. Identical QTLs for root traits from other reports with QTLs detected in this case were found, which suggests that the genetic factors responsive to local supplied NO3
– is involved in root growth and development 相似文献
18.
The effect of low irradiance on three rice cultivars (shade tolerant cvs. Swarnaprabha and CO 43 and shade susceptible cv.
IR 20) was studied. The large subunit (LSU) of ribulose-1,5-bisphosphate carboxylase/oxygenase with molecular mass of 55 kDa
was reduced in cv. IR 20 grown under low irradiance (LI). Native protein profile studied showed, under LI, reduction in the
contents of proteins with RF values 0.03, 0.11 and 0.37. Analysis of chloroplast polypeptides revealed an induction of light-harvesting
chlorphyll-protein 2 (LHCP2) under shade. The induction was more expressed in cv. CO 43 than in cv. IR 20. Under LI, in vivo
labelled protein bands in the molecular range of 26 - 27 kDa were induced. These proteins were highly turned over in the LI-grown
plants of cv. CO 43 than in cv. IR 20. A signal for rbcL gene sequences in EcoRI digested lanes was also found. Isozyme analysis
of peroxidase showed an induction of a new band with RF 0.43 in cv. IR 20 subjected to LI.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
19.
Involvement of calcium-dependent protein kinase in rice (Oryza sativa L.) lamina inclination caused by brassinolide 总被引:12,自引:0,他引:12
Promotive effect of brassinolide (BL) on green lamina inclination was concentration-dependent when excised rice (Oryza sativa L.) lamina was floated on BL solution under continuous light conditions. Protein kinase inhibitor staurosporine and Ca2+ channel blocker LaCl3 could completely, while Ca2+ chelator EGTA could partially inhibit the lamina inclination caused by BL. Two protein kinases with apparent molecular masses of 45 and 54 kDa were detected using an in-gel kinase assay with histone III-S as a substrate. In particular, the changes in 45 kDa protein kinase activity correlated with lamina inclination caused by BL. The 45 kDa kinase activity was inhibited by Ca2+ chelator EGTA, protein kinase inhibitor, staurosporine and calmodulin antagonist W-7. Therefore, this 45 kDa protein kinase was identified as a Ca2+ -dependent protein kinase (CDPK). Patterns of 2-dimensional PAGE after in vitro phosphorylation of crude extracts showed that the phosphorylation of 56 and 41 kDa proteins, which was Ca2+ -dependent, was strongly increased by BL treatment. These results suggested that CDPK and Ca2+ -dependent protein phosphorylation are involved in BL-induced rice lamina inclination. 相似文献