To copy with highly heterogeneous light environment, plants can regulate photosynthesis locally and systemically, thus maximizing the photosynthesis of individual plants. Therefore, we speculated that local weak light may induce the improvement of photosynthesis in adjacent illuminated leaves in plants. In order to test this hypothesis, maize seedlings were partially shaded, and gas exchange, chlorophyll a fluorescence and biochemical analysis were carefully assessed. It was shown that local shading exacerbated the declines in the photosynthetic rates, chlorophyll contents, electron transport and carbon assimilation-related enzyme activities in shaded leaves as plants growth progressed. While, the decreases of these parameters in adjacent illuminated leaves of shaded plants were considerably alleviated compared to the corresponding leaves of control plants. Obviously, the photosynthesis in adjacent illuminated leaves in shaded plants was improved by local shading, and the improvement in adjacent lower leaves was larger than that in adjacent upper ones. As growth progressed, local shading induced higher abscisic acid contents in shaded leaves, but it alleviated the increase in the abscisic acid contents in adjacent leaves in shaded plants. Moreover, the difference in sugar content between shaded leaves and adjacent illuminated ones was gradually increased. Consequently, local weak light suppressed the photosynthesis in shaded leaves, while it markedly improved the photosynthesis of adjacent illuminated ones. Sugar gradient between shaded leaves and adjacent illuminated ones might play a key role in photosynthetic regulation of adjacent illuminated leaves. This article is protected by copyright. All rights reserved.

中文翻译：

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局部弱光诱导玉米幼苗相邻受照叶片光合作用的改善

为了在高度异质光环境下进行复制，植物可以局部和系统地调节光合作用，从而最大限度地提高单个植物的光合作用。因此，我们推测局部弱光可能会诱导植物相邻受照叶片光合作用的改善。为了验证这一假设，玉米幼苗被部分遮蔽，并仔细评估了气体交换、叶绿素 a 荧光和生化分析。结果表明，随着植物生长的进行，局部遮荫加剧了遮荫叶片中光合速率、叶绿素含量、电子传递和碳同化相关酶活性的下降。尽管，与对照植物的相应叶片相比，这些参数在遮荫植物的相邻受光叶片中的降低明显减轻。显然，局部遮光提高了遮荫植物相邻受光叶的光合作用，且相邻下部叶片的改善大于相邻上部叶片。随着生长的进行，局部遮荫导致遮荫叶片中脱落酸含量升高，但它减轻了遮荫植物相邻叶片中脱落酸含量的增加。此外，阴影叶与相邻光照叶之间的糖含量差异逐渐增加。因此，局部弱光抑制了阴影叶片的光合作用，而显着改善了相邻光照叶片的光合作用。遮荫叶片和相邻光照叶片之间的糖梯度可能在相邻光照叶片的光合调节中起关键作用。本文受版权保护。版权所有。