花楸树（Sorbus pohuashanensis）为我国北方特有集观叶、观花、观果一体的乡土景观树种，其野生资源分布于海拔800～2200 m亚高山及高山上，其引种低海拔地区越夏产生的叶片“日灼”问题是影响其资源开发利用的关键。本项目利用电子显微技术与生理学的方法，观测花楸树夏季高温胁迫下叶片细胞超微结构和相关生理生化指标的变化，从形态、生理层面了解花楸树高温胁迫下叶片产生“日灼”的原因与应答机制；通过高通量测序技术，建立花楸树转录组和蛋白质组信息库，并通过两个组学的数据结果的关联分析，探究花楸树应答夏季高温胁迫的分子调控网络机制；借助转录组学与蛋白质组学的互补性，发掘花楸树耐热基因，为从基因水平上研究花楸树提供基础信息。研究旨在全面分析花楸树引种低海拔地区应对夏季高温胁迫的分子网络协同应答机制，为花楸树遗传改良与耐热品种选育提供理论依据。

Rowan (Sorbus pohuashanensis), a native species to north of China, has a high ornamental value due to the appearance of its leaves, flowers, and fruit in different seasons. The wild resources of this species are distributed in the subalpine and high mountains with altitude ranging from 800 to 2200 m. When it is introduced in the area of low altitude, “Leaf　sunburn” in summer is the key problem to influence its utilization. In this study, using the technology of electronic microscopy and method of physiology, the reason of “Leaf sunburn” and the physiology and biochemistry mechanism of heat-responsive in summer will be discovered. Meanwhile, through high-throughput sequencing technologies, the transcriptome and proteome information database in S. pohuashanensis will be established. And after the correlation analysis of the two omics data, the sophisticated summer heat-responsive molecular network mechanism in S. pohuashanensis will be explored at systematic biological level. In addition, genes related to heat resistant of S. pohuashanensis will be identified for further studying this species at gene level. The main aims of this study are to explore the molecular network and collaborative responsive mechanism to heat stress in summer at low altitude area and provide the basic information for genetic improvement and heat-resistant varities breeding of S. pohuashanensis.