Effect of Heat Stress on the Photosynthetic Characteristics in Flag Leaves at the Grain-Filling Stage of Different Heat-Resistant Winter Wheat Varieties
Effect of Heat Stress on the Photosynthetic Characteristics in Flag Leaves at the Grain-Filling Stage of Different Heat-Resistant Winter Wheat Varieties
复制标题
热胁迫对不同耐热冬小麦品种灌浆期旗叶光合特性的影响
DOI：
10.1111/jac.12045
复制
发表时间：
2014-04-01
影响因子：
3.5
通讯作者：
Zhang, J. W.
中科院分区：
文献类型：
--
作者：
Feng, B.;Liu, P.;Zhang, J. W.
热胁迫已成为限制小麦产量的一个越来越重要的因素。在我国北方，灌浆期高温（>30 ℃）是制约小麦增产的主要因素之一。以两种冬小麦（Triticum aestivum L.）以热胁迫敏感性不同的小麦品种济麦22 'JM 22'和新麦26 'XM 26'为材料，研究了热胁迫对小麦灌浆期光合特性的影响。结果表明，在灌浆期高温胁迫下，XM 26旗叶光合速率（Pn）下降速度快于JM 22。在高温胁迫下，光合速率下降速度比未胁迫时快，在高温胁迫后10天（10 DAS），光合速率分别下降69.9%和59.3%。这种下降的P-N不是由热诱导的气孔限制，而是由Rubisco活性下降和光系统II（PSII）的功能下降。热胁迫后，JM 22和XM 26的籽粒产量分别比对照下降了6.41%和11.43%。热胁迫也引起叶肉细胞超微结构的改变。热胁迫对细胞器的损伤较JM 22严重。此外，JM 22品种表现出一定的自我修复能力，热胁迫伤害。这些结果表明，在光合性能下降所造成的热胁迫是品种依赖性。与XM 26相比，JM 22在PSII功能和羧化活性方面具有上级的热稳定性，这两个功能和活性都对热胁迫敏感。
Heat stress has become an increasingly important factor in limiting wheat yields. In northern China, high temperature (>30 degrees C) during the grain filling is one of the major constraints in increasing wheat productivity. We used two winter wheat (Triticum aestivum L.) cultivars with different sensitivities to heat stress (Jimai 22 'JM22', low sensitivity and Xinmai 26 'XM26', high sensitivity) to study the various aspects of photosynthetic characteristics during the grain filling stage under heat stress. The results showed that photosynthesis rates (P-n) in flag leaves of XM26 decreased faster than in JM22 under heat stress during the grain-filling stage. P-n decreased more rapidly under heat stress than without stress, by up to 69.9% and 59.3%, respectively, at 10days following heat stress (10 DAS). This decline of P-n was not caused by heat-induced stomatal limitation, but rather by a decline in Rubisco activity and a functional drop in photosystem II (PSII). After heat stress, the grain yield of JM22 decreased by 6.41%, but XM26 decreased by 11.43%, when compared with their respective controls. Heat stress also caused an alteration of mesophyll cell ultrastructure. Injury caused by heat stress to organelles in XM26 was more severe than JM22. Moreover, the JM22 cultivar showed some self-repair capacity following heat stress injury. These results indicate that declines in photosynthetic performance caused by heat stress were cultivar-dependent. Compared with XM26, the JM22 cultivar had superior heat stability in terms of PSII function and carboxylation activity, both of which are susceptible to heat stress.