Scholarlink

Key message <p>We resolved that SlMYC2 positively regulated tomato leaf senescence by inhibiting ROS scavenging capacity and exacerbating oxidative damage and PSII functional decline using a darkness-induced senescence model.</p> Abstract <p>Tomato leaf senescence seriously affects its yield and quality. Jasmonic acid (JA) signaling can promote tomato leaf senescence, but the mechanism is unclear. SlMYC2, as a core transcription factor in JA signaling, may play a role in regulating leaf senescence. Therefore, this study used <i>SlMYC2</i> overexpression and silencing lines to systematically analyze the mechanism of SlMYC2 regulation of leaf senescence through a darkness-induced senescence model. The results showed SlMYC2 accelerated the leaf senescence process in tomato by increased chlorophyll degradation and malondialdehyde accumulation in <i>SlMYC2</i>-OE lines after dark treatment, and the expressions of senescence-related genes <i>SlSGR1, SlSAG12,</i> and <i>SlSAG15</i> were significantly upregulated. At the photosynthetic physiological level, <i>SlMYC2</i>-OE caused damage to photosystem II (PSII) function, with a significant decrease in maximum photochemical efficiency (<i>F</i><sub><i>v</i></sub><i>/F</i><sub><i>m</i></sub>) and performance index (<i>PI</i><sub><i>ABS</i></sub>), and exacerbated damage to the donor side (<i>W</i><sub><i>k</i></sub>). Further studies found SlMYC2 accelerated programmed cell death (PCD) by promoting the accumulation of reactive oxygen species (ROS). The contents of superoxide anion (O₂<sup>⁻·</sup>) and hydrogen peroxide (H₂O₂) significantly increased in the <i>SlMYC2</i>-OE lines, while the contents of ascorbic acid (AsA) and glutathione (GSH), as well as the activities and gene expressions of key antioxidant enzymes such as SOD, POD, CAT, APX, and GR were all inhibited. In summary, SlMYC2 has been shown to inhibit the removal of reactive oxygen species (ROS), exacerbate oxidative damage and photosystem II (PSII) function decline, and positively regulate the process of leaf senescence in tomato. This study will provide a theoretical foundation for targeting the JA signaling pathway to regulate tomato senescence.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

The regulatory role of SlMYC2 in darkness-induced leaf senescence of tomato

  • 期刊论文

  • 发表日期：

    2025年11月8日

查看全文
  • Qi Ding,
  • Hongyun Xing,
  • Ziyi Zhang,
  • Haiyan Fan,
  • Yang Yu,
  • Xiangnan Meng,
  • Na Cui

摘要

Key message

We resolved that SlMYC2 positively regulated tomato leaf senescence by inhibiting ROS scavenging capacity and exacerbating oxidative damage and PSII functional decline using a darkness-induced senescence model.

Abstract

Tomato leaf senescence seriously affects its yield and quality. Jasmonic acid (JA) signaling can promote tomato leaf senescence, but the mechanism is unclear. SlMYC2, as a core transcription factor in JA signaling, may play a role in regulating leaf senescence. Therefore, this study used SlMYC2 overexpression and silencing lines to systematically analyze the mechanism of SlMYC2 regulation of leaf senescence through a darkness-induced senescence model. The results showed SlMYC2 accelerated the leaf senescence process in tomato by increased chlorophyll degradation and malondialdehyde accumulation in SlMYC2-OE lines after dark treatment, and the expressions of senescence-related genes SlSGR1, SlSAG12, and SlSAG15 were significantly upregulated. At the photosynthetic physiological level, SlMYC2-OE caused damage to photosystem II (PSII) function, with a significant decrease in maximum photochemical efficiency (Fv/Fm) and performance index (PIABS), and exacerbated damage to the donor side (Wk). Further studies found SlMYC2 accelerated programmed cell death (PCD) by promoting the accumulation of reactive oxygen species (ROS). The contents of superoxide anion (O₂⁻·) and hydrogen peroxide (H₂O₂) significantly increased in the SlMYC2-OE lines, while the contents of ascorbic acid (AsA) and glutathione (GSH), as well as the activities and gene expressions of key antioxidant enzymes such as SOD, POD, CAT, APX, and GR were all inhibited. In summary, SlMYC2 has been shown to inhibit the removal of reactive oxygen species (ROS), exacerbate oxidative damage and photosystem II (PSII) function decline, and positively regulate the process of leaf senescence in tomato. This study will provide a theoretical foundation for targeting the JA signaling pathway to regulate tomato senescence.