Osmoregulation as a key factor in drought hardening-induced drought tolerance in Jatropha curcas
Osmoregulation as a key factor in drought hardening-induced drought tolerance in Jatropha curcas
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DOI：
10.1007/s10535-015-0509-y
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发表时间：
2015-03
影响因子：
1.5
通讯作者：
S. Yang;K. Chen;S. S. Wang-S.;M. Gong
中科院分区：
文献类型：
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作者：
S. Yang;K. Chen;S. S. Wang-S.;M. Gong
麻风树是一种具有多种商业用途的植物，干旱是其分布和生产的重要限制因素。在这项研究中，我们研究了干旱硬化在麻疯树耐旱性增强中的作用，以及渗透调节和生化途径在增强耐旱性中的作用。结果表明，10%（m/v）聚乙二醇6000干旱硬化处理两天，显着提高了麻疯树苗在干旱胁迫下的成活率，降低了丙二醛含量，减轻了电解质渗漏。叶片水势、渗透势和压力势的测量表明，干旱硬化处理可以改善麻疯树幼苗在干旱胁迫初期的水分状况。此外，在干旱硬化和随后的干旱胁迫期间，干旱硬化处理逐渐增加了相容性溶质脯氨酸、甘氨酸甜菜碱和可溶性糖的浓度。它还明显提高了甜菜碱醛脱氢酶（甘氨酸甜菜碱生物合成的关键酶）的活性，以及Δ1-吡咯啉-5-羧酸合成酶（P5CS）、谷氨酸脱氢酶、精氨酸酶和鸟氨酸转氨酶（脯氨酸生物合成中的所有关键酶）的活性。在干旱硬化和随后的干旱胁迫期间，麻疯树幼苗中P5CS基因的表达也增加，但脯氨酸脱氢酶的活性降低。这些结果表明，干旱硬化处理可以增强麻疯树的耐旱性，而渗透调节是增强麻疯树耐旱性的关键因素。
Jatropha curcas L. is a plant with various commercial uses, and drought is an important limiting factor for its distribution and production. In this study, we investigated the role of drought hardening in an increased drought tolerance in J. curcas, and the involvement of osmoregulation and biochemical pathways in this enhanced tolerance. Results show that a drought hardening treatment with 10 % (m/v) polyethylene glycol 6000 for two days significantly increased a survival rate, decreased the content of malondialdehyde, and alleviated electrolyte leakage in the J. curcas seedlings under the drought stress. Measurements of leaf water potential, osmotic potential, and pressure potential show that this drought hardening treatment can improve the water status of J. curcas seedlings during the early phase of drought stress. In addition, the drought hardening treatment gradually increased the concentrations of compatible solutes proline, glycinebetaine, and soluble sugars during drought hardening and subsequent drought stress. It also clearly raised the activity of betaine aldehyde dehydrogenase, a key enzyme for the glycinebataine biosynhthesis as well as the activity of enzymes Δ1-pyrroline-5-carboxylate synthetase (P5CS), glutamate dehydrogenase, arginase, and ornithine aminotransferase, all key enzymes in the proline biosynthesis. The expression of P5CS gene in the J. curcas seedlings also increased during drought hardening and subsequent drought stress, but the activity of proline dehydrogenase decreased. These results show that the drought hardening treatment can enhance drought tolerance in J. curcas, and osmoregulation is a key factor in this increased drought tolerance.