文献类型：期刊文献

英文题名：Proteomic insights into the photosynthetic divergence between bark and leaf chloroplasts in Salix matsudana

作者：Liu, Junxiang[1] Sun, Chao[1] Zhai, Fei-Fei[2] Li, Zhenjian[1] Qian, Yongqiang[1] Gu, Lin[1] Sun, Zhenyuan[1]

第一作者：刘俊祥

通信作者：Gu, L[1];Sun, ZY[1]

机构：[1]Chinese Acad Forestry, State Key Lab Tree Genet & Breeding, Key Lab Tree Breeding & Cultivat, State Forestry & Grassland Adm,Res Inst Forestry, Beijing 100091, Peoples R China;[2]Henan Polytech Univ, Sch Architectural & Artist Design, Jiaozuo 454000, Henan, Peoples R China

年份：2021

卷号：41

期号：11

起止页码：2142-2152

外文期刊名：TREE PHYSIOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000742398600013)】；

基金：National Key R & D Program of China (2016YFD0600105); National Natural Science Foundation of China (32071729).

语种：英文

外文关键词：bark chloroplast; corticular photosynthesis; iTRAQ proteomics; oxygen evolution; ultrastructure

摘要：Bark chloroplasts play important roles in carbon balancing by recycling internal stem CO2 into assimilated carbon. The photosynthetic response of bark chloroplasts to interior stem environments has been studied recently in woody plants. However, the molecular regulatory mechanisms underlying specific characteristics of bark photosynthesis remain unclear. To address this knowledge gap, differences in the structure, photosynthetic activity and protein expression profiles between bark and leaf chloroplasts were investigated in Salix matsudana in this study. Bark chloroplasts exhibited broader and lower grana stacks and higher levels of starch relative to leaf chloroplasts. Concomitantly, decreased oxygen evolution rates and decreased saturated radiation point were observed in bark chloroplasts. Furthermore, a total of 293 differentially expressed proteins (DEPs) were identified in bark and leaf chloroplast profile comparisons. These DEPs were significantly enriched in photosynthesis-related biological processes or Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways associated with photosynthesis. All 116 DEPs within the KEGG pathways associated with photosynthesis light reactions were downregulated in bark chloroplasts, including key proteins responsible for chlorophyll synthesis, light energy harvesting, nonphotochemical quenching, linear electron transport and photophosphorylation. Interestingly, seven upregulated proteins involved in dark reactions were identified in bark chloroplasts that comprised two kinds of malic enzymes typical of C-4-type photosynthesis. These results provide comprehensive proteomic evidence to understand the low photochemical capability of bark chloroplasts and suggest that bark chloroplasts might fix CO2 derived from malate decarboxylation.