Shi Haitao, Chan Zhu-Long
a Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture; Wuhan Botanical Garden; Chinese Academy of Sciences; Wuhan, PR China.
Plant Signal Behav. 2014;9(7):e29109. doi: 10.4161/psb.29109.
The heme-associated proteins (HAPs, also known as nuclear factor y, subunit A/B/C (NF-YA/B/C)) have been reported to bind specifically to DNA fragments containing CCAAT-box, however, the physiological functions and direct targets of these HAP proteins remain unclear in plants. In our recent study, we found that AtHAP5A and AtXTH21 positively modulated freezing stress resistance, and chromatin immunoprecipitation (ChIP) assay and genetic evidence indicated that AtHAP5A might act in the upstream of AtXTH21 in freezing stress. Moreover, AtHAP5A and AtXTH21 had significant effects on inhibiting cold stress-induced reactive oxygen species (ROS) accumulation and activating ABA-related genes' expression. Thus, a possible model that depicting AtHAP5A-mediated cold stress responses was proposed in this study, and we highlighted that AtHAP5A modulates freezing stress resistance in Arabidopsis through binding to CCAAT motif of AtXTH21, which is independent of the CBF pathway.
据报道，血红素相关蛋白（HAPs，也称为核因子Y，亚基A/B/C（NF-YA/B/C））能特异性结合含有CCAAT盒的DNA片段，然而，这些HAP蛋白在植物中的生理功能和直接作用靶点仍不清楚。在我们最近的研究中，我们发现AtHAP5A和AtXTH21正向调节抗冻胁迫能力，染色质免疫沉淀（ChIP）分析和遗传学证据表明，AtHAP5A在冻害胁迫中可能作用于AtXTH21的上游。此外，AtHAP5A和AtXTH21对抑制冷胁迫诱导的活性氧（ROS）积累和激活ABA相关基因的表达有显著影响。因此，本研究提出了一个描述AtHAP5A介导的冷胁迫反应的可能模型，并且我们强调AtHAP5A通过结合AtXTH21的CCAAT基序来调节拟南芥的抗冻胁迫能力，这一过程独立于CBF途径。
