College of Life Sciences, Shandong Agricultural University, Taian, Shandong, People's Republic of China.
Gene. 2012 Jul 15;503(1):65-74. doi: 10.1016/j.gene.2012.04.042. Epub 2012 Apr 25.
Fructose 1,6-biphosphate aldolase (FBA) is a key enzyme in plants, which is involved not only in glycolysis and gluconeogenesis in the cytoplasm, but also in the Calvin cycle in plastids. Research on FBAs in various organisms has been reported, but there is none on FBAs in Arabidopsis at the molecular level. In the current study, eight FBA family genes (AtFBA1-8) were identified and analyzed in Arabidopsis thaliana. These genes have a highly conserved aldolase-type TIM barrel domain and a C-terminal peptide, but variable N-terminal peptides. Based on the phylogenetic analysis of FBA protein sequences from Arabidopsis and other plant species, AtFBA family was classified into two subfamilies, including three members (AtFBA1-3) with high similarities to FBAs occurring at plastid, and five (AtFBA4-8) with high similarities to FBAs localized in the cytoplasm. By confocal microscopy analysis with GFP fusion protein, AtFBA3 and AtFBA4 as well as AtFBA6 were observed to be localized in the plastid and cytoplasm, respectively. At least two duplicated gene pairs of AtFBA1 and AtFBA2, as well as AtFBA4 and AtFBA8 were found. Transcript level analysis of AtFBA genes in various tissues revealed the unique and overlapping expression patterns of plastid and cytosol AtFBA genes, suggesting that these genes may function at different stages of plant growth and development. Interestingly, AtFBA1, AtFBA2, AtFBA5 and AtFBA7 showed undetectable expression in roots. The expression patterns of AtFBA genes under different stress conditions suggested that all the members showed different expression patterns in response to stresses, including ABA, NaCl, Cd, abnormal temperature and drought, and, except for AtFBA3, most of the AtFBA genes were significantly responsive to drought stress in roots. Moreover, AtFBA1, AtFBA2, AtFBA5, AtFBA7 and AtFBA8 were induced by at least one of three sugars (sucrose, glucose and fructose) after 24h of treatment. Further functional analyses indicated important clues of AtFBA2, AtFBA6 and AtFBA8 in plant growth, stress responses and development, respectively. Thus these results provide additional knowledge on AtFBA families and their roles.
果糖-1,6-二磷酸醛缩酶(FBA)是植物中的一种关键酶,不仅参与细胞质中的糖酵解和糖异生,还参与质体中的卡尔文循环。已经报道了各种生物体中 FBAs 的研究,但在分子水平上没有关于拟南芥 FBAs 的研究。在本研究中,鉴定并分析了拟南芥中的 8 个 FBA 家族基因(AtFBA1-8)。这些基因具有高度保守的醛缩酶型 TIM 桶结构域和 C 末端肽,但 N 末端肽可变。基于来自拟南芥和其他植物物种的 FBA 蛋白序列的系统发育分析,将 AtFBA 家族分为两个亚家族,包括三个与质体中发生的 FBAs 具有高度相似性的成员(AtFBA1-3),以及五个与定位于细胞质中的 FBAs 具有高度相似性的成员(AtFBA4-8)。通过 GFP 融合蛋白的共焦显微镜分析,观察到 AtFBA3 和 AtFBA4 以及 AtFBA6 分别定位于质体和细胞质中。发现至少有两对 AtFBA1 和 AtFBA2 以及 AtFBA4 和 AtFBA8 的基因重复。对各种组织中 AtFBA 基因的转录水平分析表明,质体和细胞质 AtFBA 基因具有独特和重叠的表达模式,表明这些基因可能在植物生长和发育的不同阶段发挥作用。有趣的是,AtFBA1、AtFBA2、AtFBA5 和 AtFBA7 在根中表现出无法检测到的表达。在不同胁迫条件下 AtFBA 基因的表达模式表明,所有成员都对胁迫表现出不同的表达模式,包括 ABA、NaCl、Cd、异常温度和干旱,除了 AtFBA3 之外,大多数 AtFBA 基因在根中对干旱胁迫有明显的响应。此外,AtFBA1、AtFBA2、AtFBA5、AtFBA7 和 AtFBA8 在 24 小时处理后至少有一种糖(蔗糖、葡萄糖和果糖)的处理下被诱导。进一步的功能分析表明,AtFBA2、AtFBA6 和 AtFBA8 在植物生长、胁迫响应和发育中分别具有重要作用。因此,这些结果为 AtFBA 家族及其功能提供了更多的知识。