The physiological importance of developmental mechanisms that enforce proper stomatal spacing in Arabidopsis thaliana
The physiological importance of developmental mechanisms that enforce proper stomatal spacing in Arabidopsis thaliana
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DOI：
10.1111/nph.12586
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发表时间：
2014-03-01
期刊：
影响因子：
9.4
通讯作者：
Bergmann, Dominique C.
中科院分区：
文献类型：
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作者：
Dow, Graham J.;Berry, Joseph A.;Bergmann, Dominique C.
调控气孔发育的遗传和细胞生物学机制是产生适当数量气孔和保证气孔间最小一个表皮细胞间隔的必要条件。在模式植物系统中操纵这些过程的能力使我们能够研究气孔模式和密度变化的生理重要性，从而测试气孔生物学的基础理论。本研究分析了12个因突变或转基因而具有不同气孔特征的拟南芥基因型。利用气孔性状对基因型进行分类，并预测个体气孔对水汽的最大导度（解剖g(smax)）。叶片级气体交换测量测定了扩散g（smax）、净碳同化(A)、水分利用效率（WUE）和气孔对CO2浓度增加的响应。具有适当间距的基因型（簇中气孔< 5%）在气孔密度增加10倍的情况下获得了与解剖g（smax）相当的扩散g（smax）值，而具有图案缺陷的基因型（> 19%的簇）则没有。具有聚类的基因型也降低了A和气孔响应，而WUE通常不受模式的影响。因此，每个气孔的最佳功能依赖于维持一个表皮细胞间距，气孔控制的生理参数与解剖g（smax）密切相关。
Genetic and cell biological mechanisms that regulate stomatal development are necessary to generate an appropriate number of stomata and enforce a minimum spacing of one epidermal cell between stomata. The ability to manipulate these processes in a model plant system allows us to investigate the physiological importance of stomatal patterning and changes in density, therein testing underlying theories about stomatal biology.Twelve Arabidopsis thaliana genotypes that have varied stomatal characteristics as a result of mutations or transgenes were analyzed in this study. Stomatal traits were used to categorize the genotypes and predict maximum stomatal conductance to water vapor (Anatomical g(smax)) for individuals. Leaf-level gas-exchange measurements determined Diffusive g(smax), net carbon assimilation (A), water-use efficiency (WUE), and stomatal responses to increasing CO2 concentration.Genotypes with proper spacing (< 5% of stomata in clusters) achieved Diffusive g(smax) values comparable to Anatomical g(smax) across a 10-fold increase in stomatal density, while lines with patterning defects (> 19% clustering) did not. Genotypes with clustering also had reduced A and impaired stomatal responses, while WUE was generally unaffected by patterning.Consequently, optimal function per stoma was dependent on maintaining one epidermal cell spacing and the physiological parameters controlled by stomata were strongly correlated with Anatomical g(smax).