State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China.
Plant Cell Rep. 2014 Nov;33(11):1913-20. doi: 10.1007/s00299-014-1668-6. Epub 2014 Aug 6.
The ripening-induced MaBSD1 acts as a transcriptional activator, and might be involved in banana fruit ripening partly through directly activating the expression of two ripening-associated genes, MaEXP1/2. BSD (BTF2-like transcription factors, synapse-associated proteins and DOS2-like proteins) transcription factors are characterized by a typical BSD domain. However, little information is available concerning their possible roles in plant growth and development, especially in fruit ripening. In the present study, one BSD gene, designated as MaBSD1, was isolated from banana fruit. MaBSD1 has an open reading frame (ORF) of 921 bp which encodes a polypeptide of 306 amino acid residues with molecular weight of 34.80 kDa, and isoelectric point (pI) of 4.54. Subcellular localization and transcriptional activation assays showed that MaBSD1 was localized in both the nucleus and cytoplasm and possessed transcriptional activity. RT-qPCR and promoter activity analysis indicated that MaBSD1 was ethylene and ripening inducible, and the accumulation of MaBSD1 transcript was correlated well with the evolution of ethylene production and ripening process. Moreover, transient assay showed that MaBSD1 could activate the expression of two cell wall modification-related genes, MaEXP1/2, via directly interacting with their promoters. Together, these data suggest that ripening-induced MaBSD1 acts as a transcriptional activator and might be associated with banana fruit ripening, at least partially through directly activating the expression of MaEXP1/2, expanding the limited information concerning the BSD transcription factor in relation to fruit ripening.
成熟诱导的 MaBSD1 作为一个转录激活因子，可能部分通过直接激活两个成熟相关基因 MaEXP1/2 的表达参与香蕉果实成熟。BSD（BTF2 样转录因子、突触相关蛋白和 DOS2 样蛋白）转录因子的特征是具有典型的 BSD 结构域。然而，关于它们在植物生长发育中，特别是在果实成熟过程中的可能作用的信息很少。本研究从香蕉果实中分离到一个 BSD 基因，命名为 MaBSD1。MaBSD1 有一个 921bp 的开放阅读框（ORF），编码一个 306 个氨基酸残基的多肽，分子量为 34.80kDa，等电点（pI）为 4.54。亚细胞定位和转录激活分析表明 MaBSD1 定位于细胞核和细胞质中，具有转录活性。RT-qPCR 和启动子活性分析表明 MaBSD1 受乙烯和成熟诱导，MaBSD1 转录本的积累与乙烯生成和成熟过程的演变密切相关。此外，瞬时测定表明 MaBSD1 可以通过直接与它们的启动子相互作用来激活两个细胞壁修饰相关基因 MaEXP1/2 的表达。总之，这些数据表明，成熟诱导的 MaBSD1 作为一个转录激活因子，可能与香蕉果实成熟有关，至少部分是通过直接激活 MaEXP1/2 的表达，扩展了有关 BSD 转录因子与果实成熟关系的有限信息。
