Polyamines, putrescine (PUT), spermidine (SPD) and spermine (SPM) are implicated in plants’ responses under conditions of abiotic stress. Previous research in other crops has indicated that polyamines and changes in ...Polyamines, putrescine (PUT), spermidine (SPD) and spermine (SPM) are implicated in plants’ responses under conditions of abiotic stress. Previous research in other crops has indicated that polyamines and changes in their concentrations are associated with drought tolerance under conditions of water-deficit stress;however, no information exists on cotton (Gossypium hirsutum L.). Growth chamber experiments were conducted with two cotton cultivars differing in drought tolerance, ST5288B2F (drought-sensitive) and Siokra L23 (drought-tolerant) in order to investigate the distribution of free polyamines, the effect of water-deficit stress on the polyamine metabolism of cotton reproductive units and their subtending leaves as well as the possible relationship between polyamines and drought tolerance in cotton. Our results showed that cotton ovaries contained significantly higher levels of total free polyamines compared to their subtending leaves under both control and water stress conditions. Water-deficit stress significantly increased PUT concentrations in ST5288B2F, while SPM levels significantly decreased in Siokra L23. The results indicated that water-deficit stress significantly affected cotton polyamine metabolism in reproductive structures and their subtending leaves;however, no clear relationship between drought-tolerance and changes in polyamine accumulation was established. Further research is needed to elucidate the mechanism according to which water-deficit stress affects polyamine metabolism.展开更多
Ethylene is an endogenous plant hormone that increases under adverse environmental conditions, resulting in leaf and fruit abscission and ultimately yield reduction. In cotton, however, the effects of water-deficit st...Ethylene is an endogenous plant hormone that increases under adverse environmental conditions, resulting in leaf and fruit abscission and ultimately yield reduction. In cotton, however, the effects of water-deficit stress on ethylene production have been uncertain. In this study it was hypothesized that application of an ethylene inhibitor 1-Methylcyclo- propene (1-MCP) would prevent ethylene production and result in alleviation of water-deficit stress consequences on the physiology and metabolism of the cotton flower and subtending leaf. To test this hypothesis, growth chamber experiments were conducted in 2009-2010 with treatments consisting of (C) untreated well-watered control, (C + 1MCP) well-watered plus 1-MCP, (WS) untreated water-stressed control, and (WS + 1MCP) water-stressed plus 1-MCP. The plants were subjected to two consecutive drying cycles during flowering, approximately 8 weeks after planting, and 1-MCP was foliar applied at a rate of 10g. ai/ha at the beginning of each drying cycle. The results showed that 1-MCP application had no significant effect on gas exchange functions and did not prevent reductions from water stress in leaf photosynthesis, respiration and stomatal conductance. However, application of 1-MCP resulted in a decrease in sucrose content of water-stressed pistils compared to the control indicating that 1-MCP has the potential to interfere in carbohydrate metabolism of reproductive units.展开更多
Two maize inbred lines, the foundation genotype Y478 and its derived line Z58, are widely used to breed novel maize cultivars in China, but little is known about which traits confer Z58 with superior drought tolerance...Two maize inbred lines, the foundation genotype Y478 and its derived line Z58, are widely used to breed novel maize cultivars in China, but little is known about which traits confer Z58 with superior drought tolerance and yield. In the present study, responses in growth traits, photosynthetic parameters, chlorophyll fluorescence and leaf micromorphological characteristics were evaluated in Y478 and Z58 subjected to water-deficit stress induced by PEG 6000. The derived line Z58 showed greater drought tolerance than Y478, which was associated with higher leaf relative water content (RWC), root efficiency, and strong growth recovery. Z58 showed a higher stomatal density and stomatal area under the non-stressed condition;in these traits, both genotypes showed a similar decreasing trend with increased severity of water-deficit stress. In addition, the stomatal size of Y478 declined significantly. These micromorphological differences between the two lines were consistent with changes in physiological parameters, which may contribute to the enhanced capability for growth recovery in Z58. A non-linear response of Fv/Fm to leaf RWC was observed, and Fv/Fm decreased rapidly with a further gradual decline of leaf RWC. The relationship between other chlorophyll fluorescence parameters (photochemical quenching and electron transport rate) and RWC is also discussed.展开更多
Water-deficit （WD） is a major abiotic stress constraining crop productivity worldwide. Zhenshan 97 is a drought-susceptible rice genotype, while IRAT109 is a drought-resistant one. However, the physiological basis o...Water-deficit （WD） is a major abiotic stress constraining crop productivity worldwide. Zhenshan 97 is a drought-susceptible rice genotype, while IRAT109 is a drought-resistant one. However, the physiological basis of the difference remains unclear. These two genotypes had similar total water uptake rates under both WD and well-watered （WW） conditions, and their water uptake rates under WD were significantly decreased compared with those under WW. However, the water uptake rate via the cell-to-cell pathway was significantly increased in Zhenshan 97 but decreased in IRAT109 under WD, whereas the opposite trends were observed through the apoplastic pathway. These results indicated that the stress responses and relative contributions of these two water uptake pathways were associated with rice genotype under WD. The expression levels of OsPIP2;4 and OsPIP2;5 genes were significantly higher in roots of Zhenshan 97 than in IRAT109 under the two conditions. OsPIP2;4 expression in roots was significantly up-regulated under WD, while OsPIP2;5 expression showed no significant change. These results suggest that the expression levels of OsPIP2;4 and OsPIP2;5 in rice are dependent on genotype and water availability. Compared with Zhenshan 97, IRAT109 had a higher root dry weight, water uptake rate and xylem sap flow rate, and lower leaf water potential and root porosity under WD, which might be responsible for the drought resistance in IRAT109.展开更多
Polyamines, putrescine, spermidine and spermine are low molecular weight polycations implicated in flowering and seed set and plants’ responses under adverse environmental conditions. Research in other crops has show...Polyamines, putrescine, spermidine and spermine are low molecular weight polycations implicated in flowering and seed set and plants’ responses under adverse environmental conditions. Research in other crops has shown that polyamine metabolism is greatly affected by water-deficit stress, however, no information exists on cotton (Gossypium hirsutum L.). A field study was conducted in 2011 in two contrasting locations (Fayetteville, AR, and Lubbock, TX) in order to investigate the effect of water-deficit stress during flowering on polyamine metabolism of the cotton flower and its subtending leaf. Treatments consisted of control (well watered) and water-stress (irrigation withheld for two weeks at the onset of flowering) in a split plot design. First day white flowers and their subtending leaves were collected at the end of each week of the stress period for determination of polyamine concentrations. Water-deficit stress resulted in significant increases in PUT and SPD levels of pistils and leaves compared to the control. However, pistil and leaf SPM content significantly increased under drought conditions in one location and remained unaltered in the other one. Leaf and pistil polyamine metabolism of cotton appeared to be greatly affected by limited water supply, however further research is needed to elucidate the ways polyamines can be used to increase cotton drought tolerance.展开更多
为探究我国北方地区滴灌条件下不同灌溉量及品种对玉米产量及水分利用效率的影响,通过检索中国知网、万方数据知识服务平台和Web of Science等数据库,收集2000年1月-2022年6月公开发表的相关文献74篇,提取449组产量数据和453组水分利用...为探究我国北方地区滴灌条件下不同灌溉量及品种对玉米产量及水分利用效率的影响,通过检索中国知网、万方数据知识服务平台和Web of Science等数据库,收集2000年1月-2022年6月公开发表的相关文献74篇,提取449组产量数据和453组水分利用效率(WUE)数据,对收集数据进行整合,设置最大灌溉量≤50%(W1)、>50%~60%(W_(2))、>60%~70%(W3)、>70%~80%(W_(4))、>80%~90%(W_(5))5个亏缺灌溉处理组,以最大灌溉量的>90%~100%作为对照(W_(6)),采用Meta分析方法定量分析不同灌溉量(W)和品种对玉米产量和WUE等指标的影响。结果表明:与W_(6)相比,W_(4)和W_(5)均可显著提升玉米的产量和水分利用效率(WUE),分别提升8.2%~15.2%和11.7%~16.5%;当灌溉量为W3时可维持玉米的产量且极大地提升了WUE,其效应值(SMD)分别为0.12和0.89(P<0.05);但当灌溉量为W1和W2时,产量的SMD在−0.22~0.83和(P<0.05),WUE的SMD在−0.41~0.04(P<0.05),与W6相比,产量和WUE都出现显著下降。此外,不同灌溉量下不同玉米品种对产量和WUE的影响不同,综合考虑产量和WUE,对于‘西蒙6’‘咸科858’和‘先玉1331’等水分较为敏感的品种,建议采用轻度亏缺灌溉W4和W5处理;而对于‘农华101’‘中单909’等具有一定抗旱性的品种可以进行中度亏缺灌溉处理(W_(3));对于‘均隆1217’‘先玉335’等抗旱性较强的品种,则可以按照W1和W2进行灌溉;最大限度提升WUE。综上,建议北方地区玉米生产采用最大灌溉量>70%~90%的亏缺灌溉模式,能够显著提高玉米产量和水分利用效率。展开更多
文摘Polyamines, putrescine (PUT), spermidine (SPD) and spermine (SPM) are implicated in plants’ responses under conditions of abiotic stress. Previous research in other crops has indicated that polyamines and changes in their concentrations are associated with drought tolerance under conditions of water-deficit stress;however, no information exists on cotton (Gossypium hirsutum L.). Growth chamber experiments were conducted with two cotton cultivars differing in drought tolerance, ST5288B2F (drought-sensitive) and Siokra L23 (drought-tolerant) in order to investigate the distribution of free polyamines, the effect of water-deficit stress on the polyamine metabolism of cotton reproductive units and their subtending leaves as well as the possible relationship between polyamines and drought tolerance in cotton. Our results showed that cotton ovaries contained significantly higher levels of total free polyamines compared to their subtending leaves under both control and water stress conditions. Water-deficit stress significantly increased PUT concentrations in ST5288B2F, while SPM levels significantly decreased in Siokra L23. The results indicated that water-deficit stress significantly affected cotton polyamine metabolism in reproductive structures and their subtending leaves;however, no clear relationship between drought-tolerance and changes in polyamine accumulation was established. Further research is needed to elucidate the mechanism according to which water-deficit stress affects polyamine metabolism.
文摘Ethylene is an endogenous plant hormone that increases under adverse environmental conditions, resulting in leaf and fruit abscission and ultimately yield reduction. In cotton, however, the effects of water-deficit stress on ethylene production have been uncertain. In this study it was hypothesized that application of an ethylene inhibitor 1-Methylcyclo- propene (1-MCP) would prevent ethylene production and result in alleviation of water-deficit stress consequences on the physiology and metabolism of the cotton flower and subtending leaf. To test this hypothesis, growth chamber experiments were conducted in 2009-2010 with treatments consisting of (C) untreated well-watered control, (C + 1MCP) well-watered plus 1-MCP, (WS) untreated water-stressed control, and (WS + 1MCP) water-stressed plus 1-MCP. The plants were subjected to two consecutive drying cycles during flowering, approximately 8 weeks after planting, and 1-MCP was foliar applied at a rate of 10g. ai/ha at the beginning of each drying cycle. The results showed that 1-MCP application had no significant effect on gas exchange functions and did not prevent reductions from water stress in leaf photosynthesis, respiration and stomatal conductance. However, application of 1-MCP resulted in a decrease in sucrose content of water-stressed pistils compared to the control indicating that 1-MCP has the potential to interfere in carbohydrate metabolism of reproductive units.
文摘Two maize inbred lines, the foundation genotype Y478 and its derived line Z58, are widely used to breed novel maize cultivars in China, but little is known about which traits confer Z58 with superior drought tolerance and yield. In the present study, responses in growth traits, photosynthetic parameters, chlorophyll fluorescence and leaf micromorphological characteristics were evaluated in Y478 and Z58 subjected to water-deficit stress induced by PEG 6000. The derived line Z58 showed greater drought tolerance than Y478, which was associated with higher leaf relative water content (RWC), root efficiency, and strong growth recovery. Z58 showed a higher stomatal density and stomatal area under the non-stressed condition;in these traits, both genotypes showed a similar decreasing trend with increased severity of water-deficit stress. In addition, the stomatal size of Y478 declined significantly. These micromorphological differences between the two lines were consistent with changes in physiological parameters, which may contribute to the enhanced capability for growth recovery in Z58. A non-linear response of Fv/Fm to leaf RWC was observed, and Fv/Fm decreased rapidly with a further gradual decline of leaf RWC. The relationship between other chlorophyll fluorescence parameters (photochemical quenching and electron transport rate) and RWC is also discussed.
基金jointly supported by the National Science&Technology Pillar Program(Grant No.2013BAD07B10)Research Fund for the Doctoral Program of Higher Education of China(Grant No.20110146110021)
文摘Water-deficit （WD） is a major abiotic stress constraining crop productivity worldwide. Zhenshan 97 is a drought-susceptible rice genotype, while IRAT109 is a drought-resistant one. However, the physiological basis of the difference remains unclear. These two genotypes had similar total water uptake rates under both WD and well-watered （WW） conditions, and their water uptake rates under WD were significantly decreased compared with those under WW. However, the water uptake rate via the cell-to-cell pathway was significantly increased in Zhenshan 97 but decreased in IRAT109 under WD, whereas the opposite trends were observed through the apoplastic pathway. These results indicated that the stress responses and relative contributions of these two water uptake pathways were associated with rice genotype under WD. The expression levels of OsPIP2;4 and OsPIP2;5 genes were significantly higher in roots of Zhenshan 97 than in IRAT109 under the two conditions. OsPIP2;4 expression in roots was significantly up-regulated under WD, while OsPIP2;5 expression showed no significant change. These results suggest that the expression levels of OsPIP2;4 and OsPIP2;5 in rice are dependent on genotype and water availability. Compared with Zhenshan 97, IRAT109 had a higher root dry weight, water uptake rate and xylem sap flow rate, and lower leaf water potential and root porosity under WD, which might be responsible for the drought resistance in IRAT109.
文摘Polyamines, putrescine, spermidine and spermine are low molecular weight polycations implicated in flowering and seed set and plants’ responses under adverse environmental conditions. Research in other crops has shown that polyamine metabolism is greatly affected by water-deficit stress, however, no information exists on cotton (Gossypium hirsutum L.). A field study was conducted in 2011 in two contrasting locations (Fayetteville, AR, and Lubbock, TX) in order to investigate the effect of water-deficit stress during flowering on polyamine metabolism of the cotton flower and its subtending leaf. Treatments consisted of control (well watered) and water-stress (irrigation withheld for two weeks at the onset of flowering) in a split plot design. First day white flowers and their subtending leaves were collected at the end of each week of the stress period for determination of polyamine concentrations. Water-deficit stress resulted in significant increases in PUT and SPD levels of pistils and leaves compared to the control. However, pistil and leaf SPM content significantly increased under drought conditions in one location and remained unaltered in the other one. Leaf and pistil polyamine metabolism of cotton appeared to be greatly affected by limited water supply, however further research is needed to elucidate the ways polyamines can be used to increase cotton drought tolerance.
文摘为探究我国北方地区滴灌条件下不同灌溉量及品种对玉米产量及水分利用效率的影响,通过检索中国知网、万方数据知识服务平台和Web of Science等数据库,收集2000年1月-2022年6月公开发表的相关文献74篇,提取449组产量数据和453组水分利用效率(WUE)数据,对收集数据进行整合,设置最大灌溉量≤50%(W1)、>50%~60%(W_(2))、>60%~70%(W3)、>70%~80%(W_(4))、>80%~90%(W_(5))5个亏缺灌溉处理组,以最大灌溉量的>90%~100%作为对照(W_(6)),采用Meta分析方法定量分析不同灌溉量(W)和品种对玉米产量和WUE等指标的影响。结果表明:与W_(6)相比,W_(4)和W_(5)均可显著提升玉米的产量和水分利用效率(WUE),分别提升8.2%~15.2%和11.7%~16.5%;当灌溉量为W3时可维持玉米的产量且极大地提升了WUE,其效应值(SMD)分别为0.12和0.89(P<0.05);但当灌溉量为W1和W2时,产量的SMD在−0.22~0.83和(P<0.05),WUE的SMD在−0.41~0.04(P<0.05),与W6相比,产量和WUE都出现显著下降。此外,不同灌溉量下不同玉米品种对产量和WUE的影响不同,综合考虑产量和WUE,对于‘西蒙6’‘咸科858’和‘先玉1331’等水分较为敏感的品种,建议采用轻度亏缺灌溉W4和W5处理;而对于‘农华101’‘中单909’等具有一定抗旱性的品种可以进行中度亏缺灌溉处理(W_(3));对于‘均隆1217’‘先玉335’等抗旱性较强的品种,则可以按照W1和W2进行灌溉;最大限度提升WUE。综上,建议北方地区玉米生产采用最大灌溉量>70%~90%的亏缺灌溉模式,能够显著提高玉米产量和水分利用效率。
