title: The involvement of expansins in response to water stress during leaf development in wheat.
abstract: Expansins are cell wall proteins that are generally considered to be the key regulator of cell wall extension during plant growth. In this study, we used two different wheat (Triticum aestivum L.) cultivars to demonstrate that expansins are involved in wheat leaf growth and response to water stress, by regulating the expansin activity and cell wall susceptibility to expansins. Expansin activity was associated with the relative elongation rate of leaves during leaf development, suggesting their involvement in leaf elongation. Moreover, cell wall extension characteristics and expansin gene transcription were closely involved in the leaf cell elongation region. Water stress restrains leaf growth, but the growth rate of leaves was changed after rehydration, which is consistent with the response of expansin activity to water stress. Meanwhile, increased cell wall susceptibility to expansin by water deficit played an important role in maintaining cell wall extension. Furthermore, the expansin activity in drought-resistant cultivar HF9703 was always higher than that in drought-sensitive cultivar 921842 under water stress condition, which may be correlated with the higher expansin gene expression in HF9703 versus 921842. These data provide evidence for a role of expansins in the growth and response of wheat leaves to water stress.
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, Shandong, PR China.
authors.forename: Shan
authors.initials: S
authors.lastname: Zhou
authors.affiliation: Plastic Surgery Institute, Weifang Medical University, Weifang 261053, Shandong, PR China.
authors.forename: Yang-yang
authors.initials: YY
authors.lastname: Han
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, Shandong, PR China.
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, Shandong, PR China.
authors.forename: Xiangzhu
authors.initials: X
authors.lastname: Kong
authors.affiliation: State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, Shandong, PR China. Electronic address: wangw@sdau.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
mesh_terms: D055864:Droughts; D018515:Plant Leaves / Q000254:growth & development / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D014908:Triticum / Q000235:genetics / Q000254:growth & development / Q000502:physiology*
chemical_list: D010940:Plant Proteins; C095825:expansin protein, plant
keywords: Expansin; Leaf development; Triticum aestivum L.; Water stress