干旱、脱落酸和蒸腾速率对菜豆植株中PIP水通道蛋白基因表达和丰度调控的影响。
Drought, abscisic acid and transpiration rate effects on the regulation of PIP aquaporin gene expression and abundance in Phaseolus vulgaris plants.
作者信息
Aroca Ricardo, Ferrante Antonio, Vernieri Paolo, Chrispeels Maarten J
机构信息
Division of Biological Sciences, University of California San Diego La Jolla, CA 92093-0116, USA.
出版信息
Ann Bot. 2006 Dec;98(6):1301-10. doi: 10.1093/aob/mcl219. Epub 2006 Oct 7.
BACKGROUND AND AIMS
Drought causes a decline of root hydraulic conductance, which aside from embolisms, is governed ultimately by aquaporins. Multiple factors probably regulate aquaporin expression, abundance and activity in leaf and root tissues during drought; among these are the leaf transpiration rate, leaf water status, abscisic acid (ABA) and soil water content. Here a study is made of how these factors could influence the response of aquaporin to drought.
METHODS
Three plasma membrane intrinsic proteins (PIPs) or aquaporins were cloned from Phaseolus vulgaris plants and their expression was analysed after 4 d of water deprivation and also 1 d after re-watering. The effects of ABA and of methotrexate (MTX), an inhibitor of stomatal opening, on gene expression and protein abundance were also analysed. Protein abundance was examined using antibodies against PIP1 and PIP2 aquaporins. At the same time, root hydraulic conductance (L), transpiration rate, leaf water status and ABA tissue concentration were measured.
KEY RESULTS
None of the treatments (drought, ABA or MTX) changed the leaf water status or tissue ABA concentration. The three treatments caused a decline in the transpiration rate and raised PVPIP2;1 gene expression and PIP1 protein abundance in the leaves. In the roots, only the drought treatment raised the expression of the three PIP genes examined, while at the same time diminishing PIP2 protein abundance and L. On the other hand, ABA raised both root PIP1 protein abundance and L.
CONCLUSIONS
The rise of PvPIP2;1 gene expression and PIP1 protein abundance in the leaves of P. vulgaris plants subjected to drought was correlated with a decline in the transpiration rate. At the same time, the increase in the expression of the three PIP genes examined caused by drought and the decline of PIP2 protein abundance in the root tissues were not correlated with any of the parameters measured.
背景与目的
干旱导致根系水力导度下降，除栓塞作用外，这最终由水通道蛋白控制。干旱期间，多种因素可能调节叶片和根系组织中水通道蛋白的表达、丰度和活性；其中包括叶片蒸腾速率、叶片水分状况、脱落酸（ABA）和土壤含水量。本文研究了这些因素如何影响水通道蛋白对干旱的响应。
方法
从菜豆植株中克隆出三种质膜内在蛋白（PIPs）或水通道蛋白，并在缺水4天后以及复水1天后分析其表达情况。还分析了ABA和气孔开放抑制剂甲氨蝶呤（MTX）对基因表达和蛋白质丰度的影响。使用针对PIP1和PIP2水通道蛋白的抗体检测蛋白质丰度。同时，测量根系水力导度（L）、蒸腾速率、叶片水分状况和ABA组织浓度。
主要结果
所有处理（干旱、ABA或MTX）均未改变叶片水分状况或组织ABA浓度。这三种处理导致蒸腾速率下降，并提高了叶片中PVPIP2;1基因的表达和PIP1蛋白的丰度。在根系中，只有干旱处理提高了所检测的三种PIP基因的表达，同时降低了PIP2蛋白的丰度和L。另一方面，ABA提高了根系PIP1蛋白的丰度和L。
结论
干旱处理的菜豆植株叶片中PvPIP2;1基因表达和PIP1蛋白丰度的增加与蒸腾速率的下降相关。同时，干旱导致的所检测的三种PIP基因表达增加以及根系组织中PIP2蛋白丰度的下降与所测量的任何参数均无关联。
Zotero 插件