Independent and Combined Effects of High Temperature and Drought Stress During Grain Filling on Plant Yield and Chloroplast EF-Tu Expression in Spring Wheat
Independent and Combined Effects of High Temperature and Drought Stress During Grain Filling on Plant Yield and Chloroplast EF-Tu Expression in Spring Wheat
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DOI：
10.1111/j.1439-037x.2011.00477.x
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发表时间：
2011-12-01
影响因子：
3.5
通讯作者：
Ristic, Z.
中科院分区：
文献类型：
--
作者：
Prasad, P. V. V.;Pisipati, S. R.;Ristic, Z.
高温和干旱胁迫是影响作物生长、发育和产量过程的两个最重要的环境因素之一。这两种压力通常同时出现。研究了灌浆期高温干旱胁迫对小麦（Triticum aestivum L.）生理、营养和产量性状及叶绿体蛋白合成延长因子（EF-Tu）表达的影响。两个春小麦栽培品种（Pavon-76和Seri-82）在控制温度（CT;白天/夜晚，24/14摄氏度; 16/8小时光/暗期）下从播种到抽穗生长。此后，将一半的植物暴露于高温胁迫（HT;在Exp. 1和34/22 ℃，实验室。2）、干旱胁迫（持水）或HT和干旱胁迫的组合。高温和/或干旱胁迫对水稻的生理、生长和产量性状有显著影响。多数性状不存在品种、品种与温度、品种与干旱的互作效应。在整个胁迫期间，高温下叶片光合速率的下降幅度大于干旱，高温和干旱的组合具有最低的叶片光合速率。总体而言，高温或干旱对小穗育性、粒数和产量的影响相似（约减少48- 56%）。高温使籽粒数和单粒重分别下降56%和25%，干旱使籽粒数和单粒重分别下降48%和35%。这表明，在本研究所测试的温度范围内，粒数对高温更敏感，粒重对干旱更敏感。高温和干旱胁迫之间的相互作用是显着的总干重，收获指数和小穗育性，特别是当高温胁迫严重（34/22摄氏度）。高温和干旱的复合效应大于高温或干旱单独作用对叶片叶绿素含量、粒数和收获指数的加性效应。高温胁迫和高温与干旱胁迫的复合胁迫导致EF-Tu基因在两个春小麦品种中的过量表达，而干旱胁迫单独处理则没有。
High temperature and drought stress are among the two most important environmental factors influencing crop growth, development and yield processes. These two stresses commonly occur in combination. Objectives of this research were to investigate the independent and combined effects of high temperature and drought stress during grain filling on physiological, vegetative and yield traits and expression of a chloroplast protein synthesis elongation factor (EF-Tu) of wheat (Triticum aestivum L.). Two spring wheat cultivars (Pavon-76 and Seri-82) were grown at control temperatures (CT; day/night, 24/14 degrees C; 16/8 h photo/dark period) from sowing to heading. Thereafter, one half of the plants were exposed to high temperature stress (HT; 31/18 degrees C in Exp. 1 and 34/22 degrees C in Exp. 2), drought stress (withholding water), or a combination of both HT and drought stress. There were significant influences of HT and/or drought stress on physiological, growth and yield traits. There was no cultivar or cultivar by temperature or cultivar by drought interaction effects on most traits. The decreases in leaf photosynthesis were greater at HT compared with drought alone throughout the stress period, and the combination of HT and drought had the lowest leaf photosynthetic rates. Overall, HT or drought had similar effects (about 48-56 % decrease) on spikelet fertility, grain numbers and grain yield. High temperature decreased grain numbers (by 56 % averaged across both experiments) and individual grain weight (by 25 %), while, respective decreases due to drought were 48 % and 35 %. This suggests that the grain numbers were more sensitive to HT and grain weights to drought for the range of temperatures tested in this research. The interaction between HT and drought stress was significant for total dry weights, harvest index and spikelet fertility, particularly when HT stress was severe (34/22 degrees C). The combined effects of HT and drought were greater than additive effects of HT or drought alone for leaf chlorophyll content, grain numbers and harvest index. High temperature stress and the combination of HT and drought stress but not drought stress alone resulted in the overexpression of EF-Tu in both spring wheat cultivars.