期刊
AMERICAN JOURNAL OF BOTANY
卷 99, 期 7, 页码 1249-1254出版社
WILEY
DOI: 10.3732/ajb.1200088
关键词
aquaporins; cambium; in situ hybridization; Populus; secondary growth; xylogenesis
资金
- Canada Research Chair program
- Alberta Ingenuity New Faculty Award
- NSERC
Premise of the study: Aquaporins (AQPs) are channel proteins, and their function is mostly associated with transmembrane water transport. While aquaporin genes are known to be expressed in woody poplar stems, little is known about AQP expression at the cellular level. Localization of AQP expression to particular cell and tissue types is a necessary prerequisite in understanding the biological role of these genes. Methods: Subsets of plants were subjected to 6 wk of high nitrogen fertilization (high N plants) or to a controlled drought. Experimental treatments affected cambial activity and wood anatomy. RNA in situ hybridization was used to characterize spatial expression of three AQP genes in stem cross sections. Key results : The strongest labeling consistently occurred in the cambial region and in adjacent xylem and phloem cells. Expression was also detected in rays. Contact cells exhibited high expression, while expression in other ray cells was more variable. High N plants exhibited a broader band of expression in the cambial region than plants receiving only adequate N fertilization (control plants) and plants subjected to drought. Conclusions: Water channels in stems were expressed in a manner that allows hydraulic coupling between xylem and other tissues that may serve as water reservoirs, including phloem and pith parenchyma. Expression of AQPs in rays may increase radial flow of water from xylem and phloem to the cambial region where AQPs may help sustain rapid cell division and expansion of developing vessel elements.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据