Maintenance of Photosynthesis as Leaves Age Improves Whole Plant Water Use Efficiency in an Australian Wheat Cultivar
Maintenance of Photosynthesis as Leaves Age Improves Whole Plant Water Use Efficiency in an Australian Wheat Cultivar
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DOI：
10.3390/agronomy10081102
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发表时间：
2020-07
期刊：
影响因子：
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通讯作者：
Bailey Kretzler;Cristina Rodrigues Gabriel Sales;M. Karády;Elizabete Carmo‐Silva;I. Dodd
中科院分区：
文献类型：
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作者：
Bailey Kretzler;Cristina Rodrigues Gabriel Sales;M. Karády;Elizabete Carmo‐Silva;I. Dodd
叶片水分利用效率（WUEi）常被用来预测全株水分利用效率（WUEwp），但这些指标之间很少相关。更好地了解WUEi和WUEwp之间潜在的生理关系，将有助于对这一重要植物性状进行有效的表型分析，为未来的作物育种工作提供信息。虽然WUEi在叶龄和叶位之间存在差异，但对其调控机制了解较少。在澳大利亚测定WUEi和WUEwp (cv。krichaff)和英国(cv。盖茨比)小麦品种。测定叶片老化过程中叶片气体交换的变化，并评价叶片脱落酸（ABA）和1-氨基环丙烷-1-羧酸（ACC）浓度、叶绿素含量和Rubisco活性与叶片气体交换的关系。低WUEwp基因型Gatsby随着叶片老化，CO2同化(A)下降更快。ACC浓度和Rubisco活性随叶片老化而下降，但都不能解释a的变化。此外，气孔导度（gs）和气孔对ABA的敏感性随叶片老化而变化，因此WUEi在盖茨比中最低。在澳大利亚栽培品种krichaff的叶片老化过程中，即使两种基因型的水分流失情况相似，维持A也能产生更大的生物量，从而导致更高的WUEwp。
Leaf-level water use efficiency (WUEi) is often used to predict whole plant water use efficiency (WUEwp), however these measures rarely correlate. A better understanding of the underlying physiological relationship between WUEi and WUEwp would enable efficient phenotyping of this important plant trait to inform future crop breeding efforts. Although WUEi varies across leaf age and position, less is understood about the regulatory mechanisms. WUEi and WUEwp were determined in Australian (cv. Krichauff) and UK (cv. Gatsby) wheat cultivars. Leaf gas exchange was measured as leaves aged and evaluated in relation to foliar abscisic acid (ABA) and 1-aminocyclopropane-1-carboxylic acid (ACC) concentration, chlorophyll content and Rubisco activity. Carbon dioxide (CO2) assimilation (A) declined more rapidly as leaves aged in the lower WUEwp genotype Gatsby. Both ACC concentration and Rubisco activity declined as leaves aged, but neither explained the variation in A. Further, stomatal conductance (gs) and stomatal sensitivity to ABA were unchanged as leaves aged, therefore WUEi was lowest in Gatsby. Maintenance of A as the leaves aged in the Australian cultivar Krichauff enabled greater biomass production even as water loss continued similarly in both genotypes, resulting in higher WUEwp.