Combined Proteome and Transcriptome Analysis of Heat-Primed Azalea Reveals New Insights Into Plant Heat Acclimation Memory
Combined Proteome and Transcriptome Analysis of Heat-Primed Azalea Reveals New Insights Into Plant Heat Acclimation Memory
复制标题
DOI：
10.3389/fpls.2020.01278
复制
发表时间：
2020-08
影响因子：
5.6
通讯作者：
Xiuyun Wang;Zheng Li;Binglu Liu;Hong-Wei Zhou;M. S. Elmongy;Yiping Xia
中科院分区：
文献类型：
--
作者：
Xiuyun Wang;Zheng Li;Binglu Liu;Hong-Wei Zhou;M. S. Elmongy;Yiping Xia
植物可以在先前驯化的基础上获得对不可预测的挑战的超诱导防御，但涉及驯化记忆的机制鲜为人知。本研究的目的是研究杜鹃属耐热野生种海南杜鹃的热习服记忆机制。热驯化(37℃，1h)后的2d恢复(25/18℃，昼夜)(AR-pt)并没有削弱而是提高了海南雷公藤的获得性耐热性，与未驯化的(NA-pt)相比，其表型、净光合速率和膜稳定性受到的损害更小。联合转录组和蛋白质组分析表明，在2-d恢复后，许多热响应基因仍然保持着较高的蛋白质丰度，而不是转录水平。与NA-pt相比，AR-pt植物的光合作用相关基因在高温胁迫(HS：42℃，1h)下高度丰富，大部分下降，程度较小。恢复期持续积累的叶绿体定位的热休克蛋白(HSPs)、Rubisco激活酶1(Rca 1)、伴侣蛋白60β亚单位(CPN60β)和叶绿体转录活性5号染色体(PTAC5)可能为AR-pt植物抵御随后的HS提供了装备保护，光化学效率和叶绿体结构受到的损害较小。此外，在HS早期，AR-pt的RCA1转录水平显著高于NA-pt，表明RCA1在热习服记忆中的作用比其他分子伴侣更重要。新的热诱导RCA1不是结构性表达的RCA2和RCA3，而是在长期高温(LHS：42/35℃，7d)后表现出良好的热稳定性，并在光合作用驯化过程中保持平衡的Rubisco激活状态。本研究为植物热习服记忆研究提供了新的思路，并为遗传修饰和分子育种提供了耐热性改良的候选基因。
Plants can obtain superinduction of defense against unpredictable challenges based on prior acclimation, but the mechanisms involved in the acclimation memory are little known. The objective of this study was to characterize mechanisms of heat acclimation memory in Rhododendron hainanense, a thermotolerant wild species of azalea. Pretreatment of a 2-d recovery (25/18°C, day/night) after heat acclimation (37°C, 1 h) (AR-pt) did not weaken but enhanced acquired thermotolerance in R. hainanense with less damaged phenotype, net photosynthetic rate, and membrane stability than non-acclimation pretreated (NA-pt) plants. Combined transcriptome and proteome analysis revealed that a lot of heat-responsive genes still maintained high protein abundance rather than transcript level after the 2-d recovery. Photosynthesis-related genes were highly enriched and most decreased under heat stress (HS: 42°C, 1 h) with a less degree in AR-pt plants compared to NA-pt. Sustainably accumulated chloroplast-localized heat shock proteins (HSPs), Rubisco activase 1 (RCA1), beta-subunit of chaperonin-60 (CPN60β), and plastid transcriptionally active chromosome 5 (pTAC5) in the recovery period probably provided equipped protection of AR-pt plants against the subsequent HS, with less damaged photochemical efficiency and chloroplast structure. In addition, significant higher levels of RCA1 transcripts in AR-pt compared to NA-pt plants in early stage of HS showed a more important role of RCA1 than other chaperonins in heat acclimation memory. The novel heat-induced RCA1, rather than constitutively expressed RCA2 and RCA3, showed excellent thermostability after long-term HS (LHS: 42/35°C, 7 d) and maintained balanced Rubisco activation state in photosynthetic acclimation. This study provides new insights into plant heat acclimation memory and indicates candidate genes for genetic modification and molecular breeding in thermotolerance improvement.