Chloroplast thylakoid ascorbate peroxidase PtotAPX plays a key role in chloroplast development by decreasing hydrogen peroxide in Populus tomentosa
Chloroplast thylakoid ascorbate peroxidase PtotAPX plays a key role in chloroplast development by decreasing hydrogen peroxide in Populus tomentosa
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DOI：
10.1093/jxb/erab173
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发表时间：
2021-04-21
影响因子：
6.9
通讯作者：
Lu, Hai
中科院分区：
文献类型：
--
作者：
Li, Conghui;Liu, Yadi;Lu, Hai
叶绿体发育是一个复杂的过程，对植物的生长和发育至关重要。然而，木本植物叶绿体发育的详细机制仍不清楚。在本研究中，我们发现毛白杨叶组织愈伤组织细胞中的前质体在光照下可以发育出具有复杂类囊体的叶绿体。叶绿体发育在分子和细胞水平上得到证实。转录组分析表明，与光感受器和光合作用相关的基因在叶绿体发育过程中以时间依赖的方式显著上调。在光诱导的叶绿体发育过程中，类囊体定位的PtotAPX起主要作用;在过氧化氢水平较低的过表达PtotAPX转基因毛白杨愈伤组织中，光诱导的叶绿体发育得到促进，而在过氧化氢水平较高的PtotAPX反义转基因毛白杨愈伤组织中，光诱导的叶绿体发育受到抑制。此外，外源活性氧清除剂N，N '-二甲基硫脲（DMTU）可解除PtotAPX反义转基因愈伤组织光诱导叶绿体发育的抑制。基于这些结果，我们提出PtotAPX介导的活性氧的去除在毛白杨前质体的叶绿体发育中起着关键作用。
Chloroplast development is a complex process that is critical to the growth and development of plants. However, the detailed mechanism of chloroplast development in woody plants remains unclear. In this study, we showed that chloroplasts with elaborate thylakoids could develop from proplastids in the cells of calli derived from leaf tissues of Populus tomentosa upon exposure to light. Chloroplast development was confirmed at the molecular and cellular levels. Transcriptome analysis revealed that genes related to photoreceptors and photosynthesis were significantly up-regulated during chloroplast development in a time-dependent manner. In light-induced chloroplast development, a key process was the removal of hydrogen peroxide, in which thylakoid-localized PtotAPX played a major role; light-induced chloroplast development was enhanced in PtotAPX-overexpressing transgenic P. tomentosa callus with lower levels of hydrogen peroxide, but was suppressed in PtotAPX antisense transgenic callus with higher levels of hydrogen peroxide. Moreover, the suppression of light-induced chloroplast development in PtotAPX antisense transgenic callus was relieved by the exogenous reactive oxygen species scavenging agent N,N'-dimethylthiourea (DMTU). Based on these results, we propose that PtotAPX-mediated removal of reactive oxygen species plays a key role in chloroplast development from proplastids upon exposure to light in P. tomentosa.