Overexpression of a plasma membrane aquaporin in transgenic tobacco improves plant vigor under favorable growth conditions but not under drought or salt stress
Overexpression of a plasma membrane aquaporin in transgenic tobacco improves plant vigor under favorable growth conditions but not under drought or salt stress
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DOI：
10.1105/tpc.009225
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发表时间：
2003-02-01
期刊：
影响因子：
11.6
通讯作者：
Galili, G
中科院分区：
文献类型：
--
作者：
Aharon, R;Shahak, Y;Galili, G
大多数植物的共质体水分运输是通过水通道蛋白进行的，但在有利的生长条件和非生物胁迫下，水通道蛋白对植物水分状况的贡献程度尚不清楚。为了解决这个问题，我们组成型过表达拟南芥质膜水通道蛋白，PIP1b，在转基因烟草植物。在有利的生长条件下，PIP1b过表达显著提高了植物的生长速率、蒸腾速率、气孔密度和光合效率。相比之下，PIP1b过表达在盐胁迫下没有有益的影响，而在干旱胁迫下，它有负面影响，导致更快的枯萎。我们的研究结果表明，共质体水运输通过质膜水通道蛋白代表植物生长和活力的限制因素，在有利的条件下，即使充分灌溉植物面临有限的水运输。相比之下，通过质膜水通道蛋白增强的共质体水运输在盐胁迫下可能没有任何有益的影响，并且在干旱胁迫期间具有有害的影响。
Most of the symplastic water transport in plants occurs via aquaporins, but the extent to which aquaporins contribute to plant water status under favorable growth conditions and abiotic stress is not clear. To address this issue, we constitutively overexpressed the Arabidopsis plasma membrane aquaporin, PIP1b, in transgenic tobacco plants. Under favorable growth conditions, PIP1b overexpression significantly increased plant growth rate, transpiration rate, stomatal density, and photosynthetic efficiency. By contrast, PIP1b overexpression had no beneficial effect under salt stress, whereas during drought stress it had a negative effect, causing faster wilting. Our results suggest that symplastic water transport via plasma membrane aquaporins represents a limiting factor for plant growth and vigor under favorable conditions and that even fully irrigated plants face limited water transportation. By contrast, enhanced symplastic water transport via plasma membrane aquaporins may not have any beneficial effect under salt stress, and it has a deleterious effect during drought stress.