High-quality Cymbidium mannii genome and multifaceted regulation of crassulacean acid metabolism in epiphytes  

作　　者：Weishu Fan Zheng-Shan He Mengqing Zhe Jing-Qiu Feng Le Zhang Yiwei Huang Fang Liu Jia-Lin Huang Ji-Dong Ya Shi-Bao Zhang Jun-Bo Yang Andan Zhu De-Zhu Li 

机构地区：[1]Germplasm Bank of Wild Species,Kunming Institute of Botany,Chinese Academy of Sciences,Kunming,Yunnan 650201,China [2]Kunming College of Life Science,University of Chinese Academy of Sciences,Kunming,Yunnan 650201,China [3]Key Laboratory for Economic Plants and Biotechnology,Kunming Institute of Botany,Chinese Academy of Sciences,Kunming,Yunnan 650201,China [4]Yuxi Normal University,Yuxi,Yunnan 653100,China

出　　处：《Plant Communications》2023年第5期191-207,共17页植物通讯（英文）

基　　金：funded by the Strategic Priority Research Program of the Chinese Academy of Sciences(grant no.XDB31000000)to D.-Z.L.and J.-B.Y.;CAS Pioneer Hundred Talents Program to A.Z.;the Project for Innovation Team of Yunnan Province(grant no.202105AE160012)to S.-B.Z.;the Science and Technology Basic Resources Investigation Program of China(grant no.2021FY100200)to J.-B.Y.

摘　　要：Epiphytes with crassulacean acid metabolism(CAM)photosynthesis are widespread among vascular plants,and repeated evolution of CAM photosynthesis is a key innovation for micro-ecosystem adaptation.However,we lack a complete understanding of the molecular regulation of CAM photosynthesis in epiphytes.Here,we report a high-quality chromosome-level genome assembly of a CAM epiphyte,Cymbidium mannii(Orchidaceae).The 2.88-Gb orchid genome with a contig N50 of 22.7 Mb and 27192 annotated genes was organized into 20 pseudochromosomes,82.8%of which consisted of repetitive elements.Recent expansions of long terminal repeat retrotransposon families have made a major contribution to the evolution of genome size in Cymbidium orchids.We reveal a holistic scenario of molecular regulation of metabolic physiology using high-resolution transcriptomics,proteomics,and metabolomics data collected across a CAM diel cycle.Patterns of rhythmically oscillating metabolites,especially CAM-related products,reveal circadian rhythmicity in metabolite accumulation in epiphytes.Genomewide analysis of transcript and protein level regulation revealed phase shifts during the multifaceted regulation of circadian metabolism.Notably,we observed diurnal expression of several core CAM genes(especially bCA and PPC)that may be involved in temporal fixation of carbon sources.Our study provides a valuable resource for investigating post-transcription and translation scenarios in C.mannii,an Orchidaceae model for understanding the evolution of innovative traits in epiphytes.

关 键 词：EPIPHYTES CAM photosynthesis multi-omics phase shifts rhythmic metabolites 

分 类 号：Q94[生物学—植物学]