College of Agriculture, Guizhou University, Guiyang, 550025, China.
Institute of Edible Fungi Industry Technology Research, Guizhou University, Guiyang, 550025, China.
Sci Rep. 2024 Nov 6;14(1):26892. doi: 10.1038/s41598-024-77491-7.
Autophagy is a mechanism for the degradation of cellular components in eukaryotes and plays a critical role in plant responses to abiotic stress. As a core member of the autophagy process, ATG8's role in how plants respond to heat stress remains unclear. To investigate the response of the tomato autophagy core member ATG8f to heat stress, we studied the key gene ATG8f and generated tomato lines overexpressing SlATG8f using the recombinant expression vector pBWA(V)HS. We observed that under heat stress, SlATG8f overexpression (OE) plants exhibited decreased heat tolerance compared to wild-type (WT) plants. Specifically, OE plants showed increased relative electrolyte leakage, reduced soluble solid content, elevated chlorophyll content, and higher autophagosome numbers, with less damage to chloroplasts and mitochondria. Additionally, expression of some ATG8 family genes and heat shock protein-related genes was upregulated. Moreover, SlATG8f overexpressing plants had higher pollen vitality and more intact pollen morphology. These results suggest that while SlATG8f overexpression renders plants more sensitive to heat, it helps mitigate high-temperature damage to tomato pollen by maintaining chloroplast integrity and interacting with heat shock proteins to respond to heat stress.
自噬是真核生物中细胞成分降解的一种机制，在植物应对非生物胁迫中起着关键作用。作为自噬过程的核心成员，ATG8 在植物如何应对热应激中的作用尚不清楚。为了研究番茄自噬核心成员 ATG8f 对热应激的反应，我们研究了关键基因 ATG8f，并使用重组表达载体 pBWA(V)HS 生成了过表达 SlATG8f 的番茄品系。我们观察到，在热应激下，过表达 SlATG8f (OE) 的植株与野生型 (WT) 植株相比，耐热性降低。具体而言，OE 植株表现出相对电导率增加、可溶性固形物含量降低、叶绿素含量升高和自噬体数量增加，同时叶绿体和线粒体损伤减少。此外，一些 ATG8 家族基因和热休克蛋白相关基因的表达上调。此外，SlATG8f 过表达植株的花粉活力更高，花粉形态更完整。这些结果表明，虽然 SlATG8f 的过表达使植物对热更加敏感，但它通过维持叶绿体的完整性并与热休克蛋白相互作用来应对热应激，有助于减轻高温对番茄花粉的损伤。
