Photoprotection contributes to freezing tolerance as revealed by RNA-seq profiling of Rhododendron leaves during cold acclimation and deacclimation over time.
Photoprotection contributes to freezing tolerance as revealed by RNA-seq profiling of Rhododendron leaves during cold acclimation and deacclimation over time.
复制标题
通过对杜鹃花叶片在冷驯化和脱驯化过程中的 RNA-seq 分析揭示，光保护有助于提高耐冻性
DOI：
10.1093/hr/uhab025
复制
发表时间：
2022-01-05
影响因子：
8.7
通讯作者：
Xia, Yi-Ping
中科院分区：
文献类型：
--
作者：
Liu, Bing;Zhao, Fang-Meng;Xia, Yi-Ping
冷适应（CA）和去适应（DA），这往往伴随着抗冻性（FT），碳水化合物和激素的变化，是至关重要的冬季生存，特别是在全球变暖。暖冬和/或非季节性温暖期引起的CA弱和DA过早的植物很容易因对寒冷的不良反应而受伤。因此，了解FT的分子机制是必要的。本研究利用高通量RNA-seq技术分析了越冬杜鹃“Miyo-no-Sakae”叶片CA和DA随时间的变化;这些叶片在CA期间不经历休眠，但经历光保护，并且它们在DA期间不生长。使用Mfuzz和加权基因共表达网络分析，我们确定了CA和DA每个阶段的特定转录特征，并提出了涉及共表达基因和生理性状的网络。特别是，我们发现，昼夜节律是获得最强FT的关键，昼夜节律相关基因的高表达可能与冬季糖的积累有关。此外，万年青叶在冬季表现出强有力的光保护作用，表现为非光化学猝灭值高、转录本（注释为“早期光诱导蛋白”）的高表达、颗粒堆叠的损失和类囊体的去堆积，所有这些都在DA期间得到缓解。光保护的强烈要求可能是CA期间脱落酸（阿坝）和茉莉酸（JA）含量下降的原因，阿坝和JA含量的降低可能与木质素含量的降低有关。我们的数据表明，FT在越冬叶片的分子机制是独特的，这可能是由于在冬季光保护的高要求。
Cold acclimation (CA) and deacclimation (DA), which are often accompanied by changes in freezing tolerance (FT), carbohydrates and hormones, are crucial for winter survival, especially under global warming. Plants with weak CA and premature DA caused by warm winters and/or unseasonal warm spells can be easily injured by adverse reactions to cold. Thus, understanding the molecular mechanisms of FT is imperative. In this study, we used high-throughput RNA-seq to profile the CA and DA of leaves of overwintering Rhododendron "Miyo-no-Sakae" over time; these leaves do not undergo dormancy but do undergo photoprotection during CA, and they do not grow during DA. Using Mfuzz and weighted gene coexpression network analysis, we identified specific transcriptional characteristics in each phase of CA and DA and proposed networks involving coexpressed genes and physiological traits. In particular, we discovered that the circadian rhythm is critical for obtaining the strongest FT, and high expression of circadian rhythm-related genes might be linked to sugar accumulation during winter. Furthermore, evergreen leaves exhibited robust photoprotection during winter, as revealed by high values of nonphotochemical quenching, high expression of transcripts annotated as "early light-induced proteins", loss of granum stacks and destacking of thylakoids, all of which were alleviated during DA. The strong requirement of photoprotection could be the reason for decreased abscisic acid (ABA) and jasmonic acid (JA) contents during CA, and decreases in ABA and JA contents may contribute to decreases in lignin content. Our data suggest that the molecular mechanisms of FT in overwintering leaves are unique, which may be due to the high requirements for photoprotection during winter.