Silicon decreases transpiration rate and conductance from stomata of maize plants
Silicon decreases transpiration rate and conductance from stomata of maize plants
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DOI：
10.1080/01904160600851494
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发表时间：
2006-09-01
影响因子：
2.1
通讯作者：
Zhang, Fusuo
中科院分区：
文献类型：
--
作者：
Gao, Xiaopeng;Zou, Chunqin;Zhang, Fusuo
研究了硅对玉米蒸腾速率的影响。以玉米植株为材料，直接测定了叶片和角质层的蒸腾速率和导度。在正常水分条件和干旱胁迫[营养液中聚乙二醇（PEG）浓度为20%]处理下，植物在含有和不含Si的营养液中生长。施硅量为2 mmol L-1时，叶片近轴面和远轴面的蒸腾速率和导度均显著降低，但对角质层的蒸腾速率和导度无影响。这些结果表明，硅降低蒸腾速率的作用在很大程度上应归因于气孔而不是角质层的蒸腾速率降低。用扫描电镜和光学显微镜观察了叶片近轴面和远轴面的气孔结构、元素沉积和气孔密度。结果表明，气孔形态和气孔密度的变化不能解释硅降低玉米气孔蒸腾的作用。施硅与H_4SiO_4配合施用显著提高了玉米地上部和根系中硅的含量。无论施硅与否，玉米植株地上部的硅浓度均高于根部。硅沉积在叶表皮细胞壁中，主要以聚合态SiO_2的形式存在。
To characterize the effect of silicon (Si) on decreasing transpiration rate in maize (Zea mays L.) plants, the transpiration rate and conductance from both leaves and cuticula of maize plants were measured directly. Plants were grown in nutrient solutions with and without Si under both normal water conditions and drought stress [20% polyethylene glycol (PEG) concentration in nutrient solution] treatments. Silicon application of 2 mmol L-1 significantly decreased transpiration rate and conductance for both adaxial and abaxial leaf surface, but had no effect on transpiration rate and conductance from the cuticle. These results indicate that the role of Si in decreasing transpiration rate must be largely attributed to the reduction in transpiration rate from stomata rather than cuticula. Stomatal structure, element deposition, and stomatal density on both adaxial and abaxial leaf surfaces were observed with scanning electron microscopy (SEM) and a light microscope. Results showed that changes in neither stomatal morphology nor stomatal density could explain the role of Si in decreasing stomatal transpiration of maize plants. Silicon application with H4SiO4 significantly increased Si concentration in shoots and roots of maize plants. Silicon concentration in shoots of maize plants was higher than in roots, whether or not Si was applied. Silicon deposits in cell walls of the leaf epidermis were mostly in the form of polymerized SiO2.