Shen Tingting, Jia Ning, Wei Shanshan, Xu Wenyan, Lv Tingting, Bai Jiaoteng, Li Bing
Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling and Environmental Adaptation, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China.
National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.
Antioxidants (Basel). 2022 Oct 15;11(10):2035. doi: 10.3390/antiox11102035.
Arabidopsis mitochondrial-localized heat shock protein 70-1 (mtHSC70-1) modulates vegetative growth by assisting mitochondrial complex IV assembly and maintaining reactive oxygen species (ROS) homeostasis. In addition, mtHSC70-1 affects embryo development, and this effect is mediated by auxin. However, whether mtHSC70-1 regulates vegetative growth through auxin and knowledge of the link between ROS homeostasis and auxin distribution remain unclear. Here, we found that knockout seedlings () displayed shortened roots, decreased fresh root weight and lateral root number, increased root width and abnormal root morphology. The introduction of the gene into restored the growth and development of roots to the level of the wild type. However, sugar and auxin supplementation could not help the mutant roots restore to normal. Moreover, seedlings showed a decrease in meristem length and activity, auxin transport carrier (PINs and AUX1) and auxin abundances in root tips. The application of exogenous reducing agents upregulated the levels of PINs in the mutant roots. The introduction of antioxidant enzyme genes ( or ) into the mutant rescued the PIN and local auxin abundances and root growth and development. Taken together, our data suggest that mtHSC70-1 regulates polar auxin transport through ROS homeostasis in roots.
拟南芥线粒体定位的热休克蛋白70-1（mtHSC70-1）通过协助线粒体复合物IV组装和维持活性氧（ROS）稳态来调节营养生长。此外，mtHSC70-1影响胚胎发育，且这种影响由生长素介导。然而，mtHSC70-1是否通过生长素调节营养生长以及ROS稳态与生长素分布之间的联系尚不清楚。在这里，我们发现敲除幼苗（）表现出根缩短、鲜根重和侧根数量减少、根宽度增加以及根形态异常。将基因导入可使根的生长和发育恢复到野生型水平。然而，添加糖和生长素并不能帮助突变根恢复正常。此外，幼苗的分生组织长度和活性、生长素运输载体（PINs和AUX1）以及根尖中的生长素丰度均降低。外源还原剂的应用上调了突变根中PINs的水平。将抗氧化酶基因（或）导入突变体可挽救PIN和局部生长素丰度以及根的生长和发育。综上所述，我们的数据表明mtHSC70-1通过根中的ROS稳态调节生长素极性运输。
