State Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, Shandong, People's Republic of China.
PLoS One. 2013 Apr 24;8(4):e61289. doi: 10.1371/journal.pone.0061289. Print 2013.
The nuclear factor Y (NF-Y), which is a ubiquitous transcription factor found in eukaryotes, is composed of three distinct subunits, namely, NF-YA, NF-YB, and NF-YC. Here, we firstly characterized the detailed function of the Arabidopsis NFYA1 factor. It is found that the 35S::AtNFYA1-overexpressed lines were hypersensitive to salt stress and Abscisic acid (ABA) during the early-postgermination growth stages. The transgenic lines exhibited a severe postgermination growth arrest compared with the wild-type (WT) under salt stress and ABA treatment. Interestingly, sodium tungstate, which is an ABA synthesis inhibitor, restored the salt-sensitive phenotype of the 35S::AtNFYA1 lines. Results of the qRT-PCR analysis showed that the mRNA levels of ABI3 and ABI5, as well as their downstream genes AtEM1 and AtEM6, were more greatly upregulated under salt stress during seed germination in the transgenic lines compared with those in WT. On the other hand, the NFYA1-RNAi lines were found to be insensitive to salt stress and exhibited decreased levels of ABI3, ABI5, EM1, and EM6 transcripts. Our results provide clear evidence supporting a role of AtNFYA1 in regulating postgermination growth arrest under salt stress.
核因子 Y（NF-Y）是一种普遍存在于真核生物中的转录因子，由三个不同的亚基组成，即 NF-YA、NF-YB 和 NF-YC。在这里，我们首次对拟南芥 NFYA1 因子的详细功能进行了表征。结果发现，35S::AtNFYA1 过表达系在早期萌发后生长阶段对盐胁迫和脱落酸（ABA）敏感。与野生型（WT）相比，在盐胁迫和 ABA 处理下，转基因系表现出严重的萌发后生长停滞。有趣的是，钨酸钠（一种 ABA 合成抑制剂）恢复了 35S::AtNFYA1 系的盐敏感表型。qRT-PCR 分析结果表明，在种子萌发过程中，盐胁迫下转基因系中 ABI3 和 ABI5 的 mRNA 水平以及它们的下游基因 AtEM1 和 AtEM6 的表达水平比 WT 系更高地上调。另一方面，NFYA1-RNAi 系对盐胁迫不敏感，并且 ABI3、ABI5、EM1 和 EM6 转录本的水平降低。我们的结果提供了明确的证据，证明 AtNFYA1 在调节盐胁迫下萌发后的生长停滞中发挥作用。
