College of Horticulture, Northwest A&F University, Yangling 712100, China.
Department of Biology, Duke University, Durham, NC 27708, USA.
Int J Mol Sci. 2024 Jun 26;25(13):7000. doi: 10.3390/ijms25137000.
Autophagy, a highly conserved protein degradation system, plays an important role in protecting cells from adverse environmental conditions. ATG8-INTERACTING PROTEIN1 (ATI1) acts as an autophagy receptor, but its functional mechanisms in plants' heat stress tolerance remain unclear. In this study, using LC-MS/MS, we identified malate dehydrogenase (SlMDH3) as a SlATI1-interacting protein. Further studies showed that heat stress induced the expression of and SlMDH3 co-localized with SlATI1 under both 22 °C and 42 °C heat treatment conditions. Moreover, silencing of increased the sensitivity of tomato to heat stress, as evidenced by exacerbated degradation of chlorophyll; accumulation of MDA, HO, and dead cells; increased relative conductivity; and inhibition of stress-related gene expression. Conversely, overexpression of improved tomato's heat tolerance, leading to opposite effects on physiological indicators and gene expression compared to silencing. Taken together, our study suggests that SlMDH3 interacts with SlATI1 and positively regulates tomato heat tolerance.
自噬是一种高度保守的蛋白质降解系统，在保护细胞免受不利环境条件方面发挥着重要作用。ATG8-INTERACTING PROTEIN1 (ATI1) 作为自噬受体，但它在植物耐热性中的功能机制尚不清楚。在这项研究中，我们使用 LC-MS/MS 鉴定出苹果酸脱氢酶 (SlMDH3) 是 SlATI1 的互作蛋白。进一步的研究表明，热应激诱导 和 SlMDH3 的表达，并且在 22°C 和 42°C 热处理条件下，SlMDH3 与 SlATI1 共定位于叶绿体中。此外，沉默 增加了番茄对热应激的敏感性，表现在叶绿素降解加剧；MDA、HO 和死细胞积累增加；相对电导率增加；以及应激相关基因表达受到抑制。相反，过表达 提高了番茄的耐热性，导致与 沉默相比，在生理指标和基因表达上呈现相反的效果。综上所述，我们的研究表明 SlMDH3 与 SlATI1 相互作用，并正向调控番茄的耐热性。
