Abstract:

Drought is one of the main stress factors affecting the growth and development of foxtail millet， which seriously inhibits the yield and quality of foxtail millet. Graphene oxide （GO） can effectively improve the resistance of crops to stress. To further explain the mechanism of GO improving the drought resistance ability of millet， 80 mg·L^-1 GO was used to treat Jigu 168 （drought sensitive） seedlings， and the growth， development and physiological and biochemical processes of millet were analyzed. The results showed that 80 mg·L^-1 GO treatment for 15 d could significantly improve the phenotype and root system of foxtail millet， and promote the growth and development of foxtail millet， such as plant height， biomass and root system parameters. After 7 and 15 d of GO treatment， the activity of peroxidase （POD） increased by 42.86% and 66.67%， respectively， and the activity of catalase （CAT） increased by 30.23% and 52.17%， respectively， which indicated that GO could promote the function of antioxidant system and reduce cell damage. In terms of osmotic regulation， GO significantly reduced the Na⁺/K⁺ under drought stress， which helped to maintain intracellular osmotic balance and prevent excessive water loss. In addition， the grain weight after GO treatment was significantly increased by 54.73%. Therefore， a certain content of GO could significantly promote the growth and development of foxtail millet， improve its physiological and biochemical processes， thereby improve the response ability of foxtail millet to drought stress， and ultimately increase the yield. Above results provided scientific basis for GO as soil water-retaining agent to alleviate drought stress during crop cultivation.

Key words: foxtail millet, graphene oxide, drought stress, root system parameters, physiological and biochemical processes

摘要：

干旱是抑制谷子生长发育的主要逆境因子之一，严重影响谷子的产量与品质。氧化石墨烯（graphene oxide，GO）可有效提高作物的抗逆境胁迫能力。为进一步阐释GO提高谷子抗旱能力的作用机制，采用80 mg·L^-1的GO处理冀谷168（干旱敏感型）幼苗，分析其对谷子生长发育及生理生化过程的影响。结果表明，80 mg·L^-1的GO处理15 d时，谷子植株的株高、生物量及根系参数均有明显改善，显著促进了谷子生长发育；在GO处理7、15 d 时，谷子的过氧化物酶（peroxidase，POD）活性分别增加42.86%、66.67%，过氧化氢酶（catalase，CAT）活性分别增加30.23%、52.17%，表明GO处理能促进谷子抗氧化系统功能，从而减轻细胞损伤；在渗透调节方面，干旱胁迫条件下GO显著降低了谷子植株内Na⁺/K⁺，有助于维持细胞内渗透平衡，从而阻止细胞过度失水。此外，经GO处理后谷子的穗重显著提高54.73%。由此说明，一定水平的GO处理可显著促进谷子生长发育，改善其生理生化过程，从而提高谷子对干旱胁迫的应答能力，最终表现为增加谷子产量。以上研究结果为氧化石墨烯溶液成为缓解作物种植过程中干旱胁迫的土壤保水剂提供科学依据。

关键词: 谷子, 氧化石墨烯, 干旱胁迫, 根系参数, 生理生化过程