The photo-inhibition of camphor leaves ( Cinnamomum camphora L.) by NaCl stress based on physiological, chloroplast structure and comparative proteomic analysis

PeerJ

article

Jiammin Yue¹  Dawei Shi¹  Liang Zhang¹  Zihan Zhang¹  Zhiyuan Fu¹  Qiong Ren⁴  Jinchi Zhang¹ 

[1] Co–Innovation Center for Sustainable Forestry in Southern China of Jiangsu Province & Key Laboratory of Soil and Water Conservation and Ecological Restoration, Nanjing Forestry University;Key Laboratory of Land Degradation and Ecosystem Restoration & Key Laboratory of Rehabilitation and Reconstruction of Degraded Ecosystems in Northwest China, Ningxia University;Department of Forest and Conservation Sciences, Faculty of Forestry, University of British Columbia;Jiangxi Academy of Forestry

关键词: Photosynthetic inhibition;    NaCl treatment;    Proteomic analysis;    Oxidative stress;    C. camphor;   

DOI  :  10.7717/peerj.9443

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

BackgroundThe distribution and use of camphor (Cinnamomum camphora L.) trees are constrained by increasing soil salinity in south-eastern China along the Yangtze River. However, the response mechanism of this species to salinity, especially in team of photosynthesis, are unknown.MethodsHere, we analysed themorphological, physiological, ultrastructural, and proteomic traits of camphor seedlings under NaCl (103.45 mM) treatment in pot experiments for 80 days.ResultsThe growth was limited because of photosynthetic inhibition, with the most significant disturbance occurring within 50 days. Salinity caused severe reductions in the leaf photosynthetic rate (An), stomatal conductance (gs), maximal chlorophyll fluorescence (Fm), maximum quantum yield of PSII (Fv/Fm), non-photochemical quenching (NPQ), relative quantum efficiency of PSII photochemistry (ΦPSII), photochemical quenching coefficient (qP) and photo-pigment contents (chlorophyll a (Cha), chlorophyll b (Chb), total chlorophyll (Chl)); weakened the antioxidant effects, including those of malondialdehyde (MDA), superoxide dismutase (SOD) and peroxidase (POD); and injured chloroplasts. The physiologicalresults indicated that the main reason for photo-inhibition was oxidative factors induced by NaCl. The proteomic results based on isobaric tags for relative and absolute quantitation (iTRAQ) further confirmedthat photosynthesis was the most significant disrupted process by salinity (P < 0.01) and there were 30 downregulated differentially expression proteins (DEPs) and one upregulated DEP related to restraint of the photosynthetic system, which affected photosystem I, photosystem II, the Cytochrome b6/f complex, ATP synthase and the light-harvesting chlorophyll protein complex. In addition, 57 DEPs were related to photo-inhibition by redox effect and 6 downregulated DEPs, including O2 evolving complex 33kD family protein (gi—224094610) and five other predicted proteins (gi—743921083, gi—743840443, gi—743885735, gi—743810316 and gi—743881832) were directly affected. This study provides new proteomic information and explains the possible mechanisms of photo-inhibition caused by salinity on C. camphor.

【 授权许可】

CC BY