Stomatal control in tomato with ABA-deficient roots: response of grafted plants to soil drying
Stomatal control in tomato with ABA-deficient roots: response of grafted plants to soil drying
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DOI：
10.1093/jexbot/53.373.1503
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发表时间：
2002-06-01
影响因子：
6.9
通讯作者：
Munns, R
中科院分区：
文献类型：
--
作者：
Holbrook, NM;Shashidhar, VR;Munns, R
假设，ABA产生的阿坝在干燥的土壤中是负责气孔关闭进行了测试，从ABA缺陷型番茄突变体，sitiens和flacca及其近等基因野生型亲本构建的嫁接植物。进行了三种类型的实验。在第一种类型中，在野生型和sitiens或flacca之间进行相互嫁接。气孔导度与地上部的基因型一致，而与根的基因型不一致。气孔关闭在所有的嫁接植物响应土壤干燥，无论根基因型，即无论根产生阿坝的能力。在第二种类型的实验中，将野生型芽嫁接到由一个野生型根嫁接到一个突变体（flacca或sitiens）根组成的分根系统上。从一个根系中截留水分，而另一个根系则充分浇水，使得芽没有经历任何水势下降或膨压损失。气孔关闭到一个类似的程度时，水被扣留从突变体根或野生型根。在第三种类型的实验中，将具有野生型芽和野生型或sitiens根的嫁接植物建立在可以放置在压力室内的盆中，并且随着土壤干燥，压力增加，使得芽始终保持完全膨胀。气孔随着土壤干燥而关闭，无论根是野生型还是sitiens。这些实验表明，气孔关闭响应土壤干燥可以发生在叶片水分亏缺的情况下，并不需要阿坝的根生产。来自根的化学信号导致叶中质外体阿坝水平的变化可能是气孔关闭的原因。
The hypothesis that ABA produced by roots in drying soil is responsible for stomatal closure was tested with grafted plants constructed from the ABA-deficient tomato mutants, sitiens and flacca and their near-isogenic wild-type parent. Three types of experiments were conducted. In the first type, reciprocal grafts were made between the wild type and sitiens or flacca. Stomatal conductance accorded with the genotype of the shoot, not the root. Stomates closed in all of the grafted plants in response to soil drying, regardless of the root genotype, i.e. regardless of the ability of the roots to produce ABA. In the second type of experiment, wild-type shoots were grafted onto a split-root system consisting of one wild-type root grafted to one mutant (flacca or sitiens) root. Water was withheld from one root system, while the other was watered well so that the shoots did not experience any decline in water potential or loss of turgor. Stomates closed to a similar extent when water was withheld from the mutant roots or the wild-type roots. In the third type of experiment, grafted plants with wild-type shoots and either wild-type or sitiens roots were established in pots that could be placed inside a pressure chamber, and the pressure increased as the soil dried so that the shoots remained fully turgid throughout. Stomates closed as the soil dried, regardless of whether the roots were wild type or sitiens. These experiments demonstrate that stomatal closure in response to soil drying can occur in the absence of leaf water deficit, and does not require ABA production by roots. A chemical signal from roots leading to a change in apoplastic ABA levels in leaves may be responsible for the stomatal closure.