小金海棠是全球筛选出的第一个抗缺铁黄叶病苹果基因型，是我国特有的、极为重要的种质资源。本项目一方面在生理学水平上研究不同缺铁水平、分根、去顶等处理下IAA分布及缺铁胁迫下产生的IAA信号在小金海棠体内的转导机制；另一方面在分子水平上，以实验室自主获得的小金海棠454及Solexa测序结果及已获得的与铁素吸收和转运密切相关的转录因子和功能基因为基础，克隆并分析小金海棠中的ROP家族基因，通过拟南芥abp1-5、rop突变体研究ABP1、ROP蛋白介导调控缺铁适应性反应中产生的生长素信号的转导。研究结果预计可为铁素应答IAA信号转导途径提供新的证据，并为今后挖掘苹果铁高效利用关键基因和定向改良果树优良种质打下基础。

Malus xiaojinensis is the first apple genotype identified as being resistant to iron deficiency worldwide. In this project, both distribution of the IAA and expression of the transcription factor/functional genes of which are closely related to iron uptake and transportation in Malus xiaojinensis are studied in condition of split-root, top-off and iron deficiency stress. Furthermore, with aim to pursue IAA signal transduction process as system signal and local signal, process of ABP1 and ROP being mediated the IAA signal transduction is determined by using Arabidopsis abp1 and rop mutant based on the cloned Malus xiaojinensis's ROP gene family using apple genome and Malus xiaojinensis sequencing results acquired in our lab early. Results of the research would collect a new evidence on that IAA signal transduction is induced by iron deficiency, and provide a basic knowledge for understanding molecular mechanism of iron efficiency in apple.