Potassium Uptake and Transport in Apple Roots Under Drought Stress
Potassium Uptake and Transport in Apple Roots Under Drought Stress
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DOI：
10.1016/j.hpj.2018.10.001
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发表时间：
2019-01
影响因子：
5.7
通讯作者：
Jian‐Yong Qi;Simin Sun;Lin Yang;Mingjun Li;F. Ma;Y. Zou
中科院分区：
文献类型：
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作者：
Jian‐Yong Qi;Simin Sun;Lin Yang;Mingjun Li;F. Ma;Y. Zou
钾是重要的矿质营养元素之一，在植物的许多生理过程中起着重要作用，决定着作物的产量和品质。在高等植物中，有两个典型的K+转运调控基因家族，即K+通道和K+转运蛋白。然而，很少有人知道这些渠道和转运蛋白如何分工，以应对干旱胁迫。以湖北海棠为试材进行水培试验。干旱胁迫下，K+含量降低。地上部分减少34.15%，地下部分减少3.97%。同时，通过对根系的扫描，检测了根系形态的变化。在干旱条件下，编码K+转运蛋白的基因表达上调，包括MdCHX1.3、MdCHX4.11、MdCHX4.8、MdCHX4.9、MdHKT 1和MdHAK3.2。用非侵入性微量测定技术研究了钾离子通道抑制剂CsCl对K+净内流的抑制作用，结果表明CsCl对K+净内流的抑制率为19.47%，而PMH +-ATP酶（orthovanadate，原钒酸盐）抑制剂对K+净内流的抑制率为80.99%（P< 0.05）。H+外流的趋势与K+外流的趋势相似。说明干旱胁迫下K+的吸收主要是通过转运蛋白的正向内流。这些结果表明，我们可以通过有目的地上调特定的K+转运蛋白在干旱胁迫下提高K+的吸收。这一过程可以改善苹果树的生长、产量、品质和抗逆性。
As one of the most important mineral nutrient elements, potassium (K+) plays an important role in many plant physiological processes and determines both the yield and quality of crops. There are two typical gene families that regulate K+transport in higher plants, including K+channels and K+transporters. However, little is known about how these channels and transporters divide their work in response to drought stress. In this study, the hydroponic experiment was conducted onMalus hupehensis. The K+content was found to decrease in response to drought stress inM. hupehensis, the aboveground decreased by 34.15% and the underground decreased by 3.97%. Meanwhile, the root morphology change was detected by scanning the root system. Under conditions of drought, the genes encoding K+transporters were upregulated includingMdCHX1.3, MdCHX4.11, MdCHX4.8, MdCHX4.9, MdHKT1, andMdHAK3.2. The net influx of K+was inhibited by 19.47% with the action of K+channel inhibitors (CsCl), however a significant decrease (80.99%;P< 0.05) was found in roots exposed to a PM H+-ATPase (orthovanadate) inhibitor by utilizing a non-invasive micro-test technique. The trend of H+efflux was similar to that of K+. The data suggested that the positive influx of K+through the transporter accounted for the main K+uptake under drought stress. These results suggest that we can improve the uptake of K+by purposely up-regulating specific K+transporters under drought stress. This process may improve growth, yield, quality, and stress tolerance in apple trees.