The role of 24-epibrassinolide in the regulation of photosynthetic characteristics and nitrogen metabolism of tomato seedlings under a combined low temperature and weak light stress
The role of 24-epibrassinolide in the regulation of photosynthetic characteristics and nitrogen metabolism of tomato seedlings under a combined low temperature and weak light stress
复制标题
24-表油菜素内酯对低温弱光联合胁迫下番茄幼苗光合特性和氮代谢的调控作用
DOI：
10.1016/j.plaphy.2016.06.021
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发表时间：
2016-10-01
影响因子：
6.5
通讯作者：
Guo, Shirong
中科院分区：
文献类型：
--
作者：
Shu, Sheng;Tang, Yuanyuan;Guo, Shirong
本研究旨在研究低温弱光条件下外源24-表油菜素内酯（EBR）对番茄叶片生长、光合特性、叶绿素荧光成像和氮代谢的影响。结果表明：叶面施用EBR显著缓解了低温弱光联合胁迫下番茄植株生长的抑制作用，提高了番茄植株的鲜重和干重；在低温弱光条件下，EBR提高了PSII的净光合速率（Pn）、光饱和点（LSP）、最大光化学量子产率（Fv/Fm）、实际光化学效率（OPSII）和光化学猝灭系数（qP），降低了细胞间CO2浓度（Ci）、光补偿点（LCP）和表观量子效率（AQE）。此外，EBR处理番茄叶片显著提高了硝酸盐还原酶（NR）、谷氨酸脱氢酶（GDH）、谷氨酰胺合成酶（GS）和谷氨酸合成酶（GOGAT）活性，降低了铵含量和亚硝酸盐还原酶（NiR）活性。结果表明，在低温和光照联合胁迫下，EBR显著提高了天冬氨酸、苏氨酸、丝氨酸、甘氨酸和苯丙氨酸的含量，降低了半胱氨酸、蛋氨酸、精氨酸和脯氨酸的积累。综上所述，EBR可以缓解胁迫对植物光合作用和氮代谢的影响，从而促进植物生长。(C) 2016年由Elsevier Masson SAS出版。
In the present study, we aimed to investigate the effects of exogenous 24-epibrassinolide (EBR) on growth, photosynthetic characteristics, chlorophyll fluorescence imaging, and nitrogen metabolism of tomato leaves under low temperature and weak light conditions. The results showed that foliar application of EBR significantly alleviated the inhibition of plant growth, and increased the fresh and dry weights of tomato plants under a combined low temperature and weak light stress. Moreover, EBR also increased the net photosynthetic rate (Pn), light saturation point (LSP), maximal quantum yield of PSII photochemistry (Fv/Fm), actual photochemical efficiency of PSII (OPSII), and photochemical quenching coefficient (qP), but decreased the intercellular CO2 concentration (Ci), light compensation point (LCP) and apparent quantum efficiency (AQE) under low temperature and weak light conditions. In addition, application of EBR to tomato leaves significantly enhanced the activities of nitrate reductase (NR), glutamate dehydrogenase (GDH), glutamine synthetase (GS), and glutamate synthase (GOGAT), but decreased the ammonium content and nitrite reductase (NiR) activity. We observed that EBR remarkably increased the contents of aspartic acid, threonine, serine, glycine, and phenylalanine, while decreasing the accumulation of cysteine, methionine, arginine, and proline under a combined low temperature and light stress. These results suggest that EBR could alleviate the combined stress-induced harmful effects on photosynthesis and nitrogen metabolism, thus leading to improved plant growth. (C) 2016 Published by Elsevier Masson SAS.