Effect of drought stress on sugar metabolism in leaves and roots of soybean seedlings
Effect of drought stress on sugar metabolism in leaves and roots of soybean seedlings
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DOI：
10.1016/j.plaphy.2019.11.003
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发表时间：
2020-01-01
影响因子：
6.5
通讯作者：
Xie, Futi
中科院分区：
文献类型：
--
作者：
Du, Yanli;Zhao, Qiang;Xie, Futi
蔗糖是植物光合作用的主要产物，是植物生长的主要能量底物和信号调节剂。此外，蔗糖参与了对各种非生物胁迫的响应。但蔗糖在大豆（Glycine max L.）干旱胁迫下的生长和发育基本上仍不清楚。在盆栽条件下，对两个大豆品种（沈农8号（CV.SN8）和沈农12号（CV.SN12））进行了15 d的水分处理：土壤含水量为田间持水量的75 ± 5%（CK）、45 ± 5%（MD）和30 ± 5%（SD）。在干旱胁迫下，两个大豆品种地上部生物量的减少比根系生物量的减少更明显，导致更高的根冠比。干旱胁迫增加了叶片中可溶性糖和蔗糖的含量，降低了淀粉的含量;在根中，所有这些参数都增加了。这可能与干旱胁迫下糖代谢活性增强有关，包括糖代谢相关酶的活性以及GrnSPS、GmSuSy、GmC-INV、GrnA-INV、GmAMY 3和GmBAM 1的表达水平发生显著变化。此外，干旱胁迫下大豆幼苗叶片和根中蔗糖转运蛋白基因（GmSUC 2、GmSWEET 6和GmSWEET 15）的表达水平上调。因此，干旱胁迫下大豆体内糖的分配、代谢和运输发生了变化，从而导致了R/S比值的增加，这是大豆抗旱性的重要原因。
Sucrose is the main photosynthetic product in plants, and acts as a major energy substrate and signaling regulator of plant growth. Furthermore, sucrose is involved in the responses to various abiotic stresses. However, the role of sucrose in soybean (Glycine max L.) growth and development under drought stress remains largely unknown. In this study, the two soybean cultivars, Shennong8 (CV.SN8) and Shennong12 (CV.SN12), were grown in pot culture and subjected to three water treatments for 15 days: soil moisture contents of 75 +/- 5% (CK), 45 +/- 5% (MD), and 30 +/- 5% (SD) of field capacity. Under drought stress, the reduction in shoot biomass was more pronounced than the reduction of biomass in the root of both soybean cultivars, resulting in higher root/shoot (R/S) ratio. Drought stress increased the contents of soluble sugar and sucrose in the leaves, but decreased starch content; in the roots, all of these parameters were increased. This may be related to the enhanced carbohydrate metabolism activity under drought stress, including notable changes in the activities of sugar metabolism enzymes and expression levels of GrnSPS, GmSuSy, GmC-INV, GrnA-INV, GmAMY3, and GmBAM1. Furthermore, the expression levels of sucrose transporter genes (GmSUC2, GmSWEET6, and GmSWEET15) in leaves and roots of soybean seedlings were up-regulated under drought stress. In conclusion, our results highlight that the increase in R/S ratio caused by the changes of sugar allocation, metabolism, and transport under drought stress contributes towards drought resistance of soybean.