火龙果响应PEG模拟干旱胁迫的转录组分析  

Transcriptome analysis of pitaya response to PEG simulated drought stress

作　　者：王爱华[1,2] 马红叶 罗克明 文晓鹏[1] WANG Aihua;MA Hongye;LUO Keming;WEN Xiaopeng(Institute of Agro-bioengineering,College of Life Sciences,Guizhou University/Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region,Ministry of Education/Collaborative Innovation Center for Mountain Ecology&Agro-Bioengineering(CICMEAB),Guiyang 550025,Guizhou,China;Institute of Horticulture Research(Guizhou Horticultural Engineering Technology Research Center),Guizhou Academy of Agricultural Sciences,Guiyang 550006,Guizhou,China)

机构地区：[1]贵州大学农业生物工程研究院/生命科学学院·山地植物资源保护与保护种质创新教育部重点实验室·山地生态与农业生物工程协同创新中心,贵阳550025 [2]贵州省农业科学院园艺研究所(贵州省园艺工程技术研究中心),贵阳550006

出　　处：《果树学报》2022年第7期1167-1182,共16页Journal of Fruit Science

基　　金：国家自然科学基金项目(31760566,32060663)。

摘　　要：【目的】鉴定干旱胁迫响应相关基因及生化代谢途径。【方法】比较分析火龙果品种紫红龙(Hylocereus spp.‘Zihonglong’)在正常供水和聚乙二醇(polyethylene glycol,PEG)模拟干旱胁迫(-4.9 MPa)条件下的生理及转录组差异。【结果】干旱胁迫增强了丙二醛(malondialdehyde,MDA)含量、过氧化氢酶(catalase,CAT)和过氧化物酶(peroxidase,POD)活性。通过对转录组数据分析,共筛选出432个DEGs,2个比较组中共同表达的DEGs有18个,OS6H vs NS6H比较组特异表达的DEGs有288个,OS3D vs NS3D比较组特异表达的DEGs有126个。这些基因主要参与了信号转导(如植物激素、cGMP-PKG、Ras、磷脂酰肌醇等)、碳水化合物(蔗糖和淀粉、丙酮酸代谢及糖酵解等代谢)、氨基酸(如丙氨酸、谷氨酸、酪氨酸、半胱氨酸及谷胱甘肽等)代谢、转录和翻译(RNA降解、核糖体及胞吞)、次生代谢(类黄酮、苯丙烷等)及脂质代谢(а-亚麻酸代谢、甘油磷脂代谢及角质、木栓质和蜡的生物合成)等。【结论】初步明确了火龙果幼苗响应干旱胁迫的分子机制,干旱胁迫启动了火龙果一系列的信号转导途径,调控下游基因表达,通过碳水化合物的降解和转化、氨基酸代谢及次生代谢等增强了火龙果的渗透调节和解毒能力。【Objective】Pitaya(Hylocereus spp.), also known as dragon fruit, is a member of the family Cactaceae. The pitaya cultivation area is expanding rapidly in many tropical and subtropical areas worldwide because it produces a nutritionally valuable fruit with an exotic appearance, striking colors,and health-promoting properties. Moreover, pitaya is a highly drought-tolerant plant, making it an excellent species for mining plant drought-tolerance genes. Previous studies on pitaya plant responses to drought stress mostly involved physiological and biochemical analyses, with some applying microarray technologies to detect drought-related expressed sequence tags. To date, however, transcriptomic data on pitaya have been very limited. Moreover, the combination of physiological and transcriptomic analysis to better understand the response mechanism of pitaya to drought stress has not been reported so far.The objective of this study was to decipher the response mechanism of pitaya to drought and provide the theoretical basis for breeding new drought-resistant germplasm.【Methods】The pitaya stems regarding their physiological characteristics and transcript levels between the control and drought stress simulated using polyethylene glycol(PEG)6000(-4.9 MPa) were compared. Seedlings not subjected to drought stress(0 MPa) were used as the control. At specific post-treatment time-points(0, 6, 12, and 18 h as well as 1, 3, 5, and 7 days), six pitaya stems of each time-point from stressed and the control were collected, immediately frozen in liquid nitrogen, and stored at-80 °C prior to analyzing their malondialdehyde(MDA) content, catalase(CAT) and peroxidase(POD) activities. Based on the physiological responses, 6 h and 3 days were selected as the optimal sampling time for the transcriptome assay. Therefore, pitaya seedlings exposed to drought stress for 6 h and 3 days were designated as OS6H and OS3D,respectively, with the corresponding controls designated as NS6H and NS3D, respectively. |Fold Change|≥ 2 and FDR < 0.01

关 键 词：火龙果 干旱胁迫 转录组 差异表达基因 

分 类 号：S667.9[农业科学—果树学]