Studies on the temperature (T) responses of photosynthesis and leaf hydraulic conductance (Kleaf ) are important to plant gas exchange. In this study, the temperature responses of photosynthesis and Kleaf were studied in Shanyou 63 (Oryza sativa) and Yannong 19 (Triticum aestivum). Leaf water potential (Ψleaf ) was insensitive to T in Shanyou 63, while it significantly decreased with T in Yannong 19. The differential Ψleaf  - T relationship partially accounted for the differing gm -T relationships, where gm was less sensitive to T in Yannong 19 than in Shanyou 63. With different gm -T and Ψleaf -T relationships, the temperature responses of photosynthetic limitations were surprisingly similar between the two lines, and the photosynthetic rate was highly correlated with gm . With the increasing T, Kleaf increased in Shanyou 63 while it decreased in Yannong 19. The different Kleaf -T relationships were related to different Ψleaf -T relationships. When excluding the effects of water viscosity and Ψleaf , Kleaf was insensitive to T in both lines. gm and Kleaf were generally not coordinated across different temperatures. This study highlights the importance of Ψleaf on leaf carbon and water exchanges, and the mechanisms for the gm -T and Kleaf -T relationships were discussed.

中文翻译：

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水稻和小麦光合作用和叶片水力传导的温度响应。

研究光合作用的温度（T）反应和叶片水力传导率（Kleaf）对于植物气体交换非常重要。在这项研究中，研究了汕优63（Oryza sativa）和延农19（Triticum aestivum）的光合作用和Kleaf的温度响应。汕优63的叶片水势（Ψleaf）对T不敏感，而烟农19随T显着下降。差异的Ψle-T关系部分解释了不同的gm -T关系，其中gm对was农19的T敏感性较弱。与汕优63相比。在不同的gm -T和Ψle-T关系下，两株系的光合极限温度响应惊人地相似，并且光合速率与gm高度相关。随着T的增加 汕优63的Kleaf上升而延农19的Kleaf下降。不同的Kleaf -T关系与不同的Ψle-T关系有关。当排除水粘度和and叶的影响时，Kleaf对这两条线中的T不敏感。gm和Kleaf通常不会在不同温度下协调。这项研究强调了叶对叶片碳和水交换的重要性，并讨论了gm -T和Kleaf -T关系的机制。