title: Responses of leaf stomatal density to water status and its relationship with photosynthesis in a grass.
abstract: Responses of plant leaf stomatal conductance and photosynthesis to water deficit have been extensively reported; however, little is known concerning the relationships of stomatal density with regard to water status and gas exchange. The responses of stomatal density to leaf water status were determined, and correlation with specific leaf area (SLA) in a photosynthetic study of a perennial grass, Leymus chinensis, subjected to different soil moisture contents. Moderate water deficits had positive effects on stomatal number, but more severe deficits led to a reduction, described in a quadratic parabolic curve. The stomatal size obviously decreased with water deficit, and stomatal density was positively correlated with stomatal conductance (g(s)), net CO(2) assimilation rate (A(n)), and water use efficiency (WUE). A significantly negative correlation of SLA with stomatal density was also observed, suggesting that the balance between leaf area and its matter may be associated with the guard cell number. The present results indicate that high flexibilities in stomatal density and guard cell size will change in response to water status, and this process may be closely associated with photosynthesis and water use efficiency.
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Haidian, Beijing 100093, PR China.
authors.forename: Zhenzhu
authors.initials: Z
authors.lastname: Xu
authors.forename: Guangsheng
authors.initials: G
authors.lastname: Zhou
mesh_terms: D010788:Photosynthesis; D018515:Plant Leaves / Q000737:chemistry / Q000502:physiology; D054046:Plant Stomata / Q000737:chemistry* / Q000502:physiology; D018526:Plant Transpiration; D006109:Poaceae / Q000737:chemistry* / Q000502:physiology; D014867:Water / Q000378:metabolism
chemical_list: D014867:Water