Liang Le, Tang Wen, Lian Huashan, Sun Bo, Huang Zhi, Sun Guochao, Li Xiaomei, Tu Lihua, Li Huanxiu, Tang Yi
College of Horticulture, Sichuan Agricultural University, Chengdu, Sichuan, China.
Horticulture Research Institute, Chengdu Agricultural College, Chengdu, Sichuan, China.
Front Plant Sci. 2022 Dec 15;13:1074889. doi: 10.3389/fpls.2022.1074889. eCollection 2022.
Heat stress can limit vegetable growth, and this can lead to constraints on agricultural production. Grafting technologies, however, can be used to alleviate various plant stresses.
In this study, the differences in the heat stress impacts and recovery abilities of pumpkin and luffa rootstocks for bitter gourd were analyzed in terms of their antioxidant activity and carbon and nitrogen metabolism.
Compared with the un-grafted and self-grafted bitter gourd, which suffered from heat stress at 40°C for 24 h, heterologously grafted bitter gourd showed higher heat stability of the cell membrane (relative conductivity and malondialdehyde content were reduced), reduced oxidative stress (antioxidant enzyme activity was increased and the reactive oxygen species content reduced), and increased enzyme activity (sucrose phosphate synthase, sucrose synthase, neutral invertase, and acid invertase) and sugar content (soluble sugar, sucrose, fructose, and glucose) in carbon metabolism. The enzyme activity (nitrate reductase, nitrite reductase, and glutamine synthetase) and product content (nitrate and nitrite) of nitrogen metabolism were also found to be increased, and this inhibited the accumulation of ammonium ions. After the seedlings were placed at 25°C for 24 h, the heterogeneous rootstocks could rapidly restore the growth of the bitter gourd seedlings by promoting the antioxidant and carbon and nitrogen metabolism systems. When luffa was used as rootstock, its performance on the indexes was better than that of pumpkin. The correlation between the various indicators was demonstrated using a principal component and correlation analysis.
The luffa rootstock was found to be more conducive to reducing cell damage and energy loss in bitter gourd seedlings caused by heat induction through the maintenance of intracellular redox homeostasis and the promotion of carbon and nitrogen metabolism.
热应激会限制蔬菜生长，进而对农业生产造成制约。然而，嫁接技术可用于缓解多种植物胁迫。
本研究从抗氧化活性以及碳氮代谢方面，分析了苦瓜的南瓜和丝瓜砧木在热应激影响和恢复能力上的差异。
与在40°C下遭受24小时热应激的未嫁接和自嫁接苦瓜相比，异源嫁接苦瓜表现出更高的细胞膜热稳定性（相对电导率和丙二醛含量降低），氧化应激减轻（抗氧化酶活性增加，活性氧含量降低），碳代谢中的酶活性（蔗糖磷酸合酶、蔗糖合酶、中性转化酶和酸性转化酶）和糖含量（可溶性糖、蔗糖、果糖和葡萄糖）增加。氮代谢的酶活性（硝酸还原酶、亚硝酸还原酶和谷氨酰胺合成酶）和产物含量（硝酸盐和亚硝酸盐）也有所增加，这抑制了铵离子的积累。将幼苗置于25°C下24小时后，异源砧木可通过促进抗氧化以及碳氮代谢系统，迅速恢复苦瓜幼苗的生长。当使用丝瓜作为砧木时，其在各项指标上的表现优于南瓜。通过主成分分析和相关性分析证明了各项指标之间的相关性。
研究发现，丝瓜砧木通过维持细胞内氧化还原稳态以及促进碳氮代谢，更有利于减少热诱导对苦瓜幼苗造成的细胞损伤和能量损失。
