Qu Mingnan, Hamdani Saber, Li Wenzhen, Wang Shimei, Tang Jiuyou, Chen Zhuo, Song Qingfeng, Li Ming, Zhao Honglong, Chang Tiangen, Chu Chengcai, Zhu Xinguang
CAS-Key Laboratory for Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Room 106, Physiology Building, 320 Yueyang Road, Shanghai 200031, China.
The State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, 1 Beichen South road, Chinese Academy of Sciences, Beijing 100101, China.
Funct Plant Biol. 2016 Aug;43(8):727-738. doi: 10.1071/FP15348.
Light inside a canopy constantly fluctuates. Under fluctuating light (FL) conditions, stomatal conductance and photosynthetic rate constantly change. In this study, we explored whether this dynamics of stomata movements upon FL influenced the water use efficiency of rice in the field. We used a USDA-curated rice mini-core diversity panel consisting of 204 worldwide distributed accessions. A priori model on dynamic stomatal response to FL was utilised to identify kinetic parameters describing the stomatal delays during the closing (τcl) and the opening (τop) phase. Result showed that τcl had a larger variation than τop across the mini-core panel. τcl was negatively correlated with water use efficiency (WUE) related traits, stem diameter, grain weight per tiller and heading time, but positively correlated with maximum annual temperature, carbon assimilation related traits and biomass (P<0.05). We further showed a strong correlation of τcl with the relative decrease of biomass under drought in 14 accessions with different τcl. We discussed the adjustment of stomatal conductance under fluctuating light in light of the trade-off between optimising CO2 uptake and optimising water saving. This study suggests that stomatal dynamics under fluctuating light is closely related to drought resistance and hence detailed study is needed to enable its application in breeding drought tolerance in rice.
冠层内部的光照不断波动。在波动光照（FL）条件下，气孔导度和光合速率不断变化。在本研究中，我们探究了FL下气孔运动的这种动态变化是否会影响田间水稻的水分利用效率。我们使用了一个由美国农业部整理的水稻微型核心多样性面板，该面板由204份全球分布的种质组成。利用动态气孔对FL响应的先验模型来确定描述气孔关闭（τcl）和开放（τop）阶段延迟的动力学参数。结果表明，在整个微型核心面板中，τcl的变化比τop大。τcl与水分利用效率（WUE）相关性状、茎直径、单蘖粒重和抽穗期呈负相关，但与年最高温度、碳同化相关性状和生物量呈正相关（P<0.05）。我们进一步表明，在14份具有不同τcl的种质中，τcl与干旱条件下生物量的相对降低密切相关。我们根据优化二氧化碳吸收和优化节水之间的权衡，讨论了波动光照下气孔导度的调节。本研究表明，波动光照下的气孔动态与抗旱性密切相关，因此需要进行详细研究，以便将其应用于水稻耐旱性育种。
