Pomology Institute, Shanxi Agricultural University, Taiyuan, Shanxi, China.
Shanxi Key Laboratory of Germplasm Improvement and Utilization in Pomology, Taiyuan, Shanxi, China.
PeerJ. 2022 Mar 18;10:e12921. doi: 10.7717/peerj.12921. eCollection 2022.
Drought acts as a major abiotic stress that hinders plant growth and crop productivity. It is critical, as such, to discern the molecular response of plants to drought in order to enhance agricultural yields under droughts as they occur with increasing frequency. Pear trees are among the most crucial deciduous fruit trees worldwide, and yet the molecular mechanisms of drought tolerance in field-grown pear remain unclear. In this study, we analyzed the differences in transcriptome profiles of pear leaves, branches, and young fruits in irrigation field-drought conditions over the growing seasons. In total, 819 differentially expressed genes (DEGs) controlling drought response were identified, among which 427 DEGs were upregulated and 392 DEGs were downregulated. Drought responsive genes were enriched significantly in monoterpenoid biosynthesis, flavonoid biosynthesis, and diterpenoid biosynthesis. Fourteen phenylpropanoid, five flavonoid, and four monoterpenoid structural genes were modulated by field drought stress, thereby indicating the transcriptional regulation of these metabolic pathways in fruit exposed to drought. A total of 4,438 transcription factors (TFs) belonging to 30 TF families were differentially expressed between drought and irrigation, and such findings signal valuable information on transcriptome changes in response to drought. Our study revealed that pear trees react to drought by modulating several secondary metabolic pathways, particularly by stimulating the production of phenylpropanoids as well as volatile organic compounds like monoterpenes. Our findings are of practical importance for agricultural breeding programs, while the resulting data is a resource for improving drought tolerance through genetic engineering of non-model, but economically important, perennial plants.
干旱作为一种主要的非生物胁迫因素，会阻碍植物的生长和作物的生产力。因此，识别植物对干旱的分子响应对于提高农业产量至关重要，因为干旱的发生频率正在增加。梨树是世界上最重要的落叶果树之一，但在田间生长的梨对干旱的耐受机制尚不清楚。在这项研究中，我们分析了梨叶片、树枝和幼果在生长季节田间干旱条件下转录组谱的差异。共鉴定出 819 个控制干旱响应的差异表达基因（DEGs），其中 427 个上调，392 个下调。干旱响应基因在单萜生物合成、类黄酮生物合成和二萜生物合成中显著富集。14 个苯丙烷、5 个类黄酮和 4 个单萜结构基因受到田间干旱胁迫的调节，表明这些代谢途径在受干旱胁迫的果实中存在转录调控。在干旱和灌溉之间，共鉴定出 4438 个属于 30 个 TF 家族的转录因子（TFs），这些发现表明了转录组对干旱响应的变化情况，为研究提供了有价值的信息。我们的研究表明，梨树通过调节几种次生代谢途径来应对干旱，特别是通过刺激苯丙烷和单萜等挥发性有机化合物的产生。我们的研究结果对农业育种计划具有实际意义，同时，所产生的数据为通过遗传工程提高非模式但经济重要的多年生植物的耐旱性提供了资源。
