The interaction of banana MADS-box protein MuMADS1 and ubiquitin-activating enzyme E-MuUBA in post-harvest banana fruit

Key message

The interaction of MuMADS1 and MuUBA in banana was reported, which will help us to understand the mechanism of the MADS-box gene in regulating banana fruit development and ripening.

Abstract

The ubiquitin-activating enzyme E1 gene fragment MuUBA was obtained from banana (Musa acuminata L.AAA) fruit by the yeast two-hybrid method using the banana MADS-box gene MuMADS1 as bait and 2-day post-harvest banana fruit cDNA library as prey. MuMADS1 interacted with MuUBA. The interaction of MuMADS1 and MuUBA in vivo was further proved by bimolecular fluorescence complementation assay. Real-time quantitative PCR evaluation of MuMADS1 and MuUBA expression patterns in banana showed that they are highly expressed in the ovule 4 stage, but present in low levels in the stem, which suggests a simultaneously differential expression action exists for both MuMADS1 and MuUBA in different tissues and developmental fruits. MuMADS1 and MuUBA expression was highly stimulated by exogenous ethylene and suppressed by 1-methylcyclopropene. These results indicated that MuMADS1 and MuUBA were co-regulated by ethylene and might play an important role in post-harvest banana fruit ripening.     

Banana Ovate Family Protein MaOFP1 and MADS-Box Protein MuMADS1 Antagonistically Regulated Banana Fruit Ripening

The ovate family protein named MaOFP1 was identified in banana (Musa acuminata L.AAA) fruit by a yeast two-hybrid (Y2H) method using the banana MADS-box gene MuMADS1 as bait and a 2 day postharvest (DPH) banana fruit cDNA library as prey. The interaction between MuMADS1 and MaOFP1 was further confirmed by Y2H and Bimolecular Fluorescence Complementation (BiFC) methods, which showed that the MuMADS1 K domain interacted with MaOFP1. Real-time quantitative PCR evaluation of MuMADS1 and MaOFP1 expression patterns in banana showed that they are highly expressed in 0 DPH fruit, but present in low levels in the stem, which suggests that simultaneous but different expression patterns exist for both MuMADS1 and MaOFP1 in different tissues and developing fruits. Meanwhile, MuMADS1 and MaOFP1 expression was highly stimulated and greatly suppressed, respectively, by exogenous ethylene. In contrast, MaOFP1 expression was highly stimulated while MuMADS1 was greatly suppressed by the ethylene competitor 1-methylcyclopropene (1-MCP). These results indicate that MuMADS1 and MaOFP1 are antagonistically regulated by ethylene and might play important roles in postharvest banana fruit ripening.     

甘蓝型油菜BnaCIPK15基因的表达分析与功能鉴定

CBL-CIPK是高等植物中广泛存在的一类解析Ca~(2+)信号的蛋白。该研究在前期工作基础上,对甘蓝型油菜(Brassica napus L.)的BnaCIPK15基因进行了亚细胞定位、双分子荧光互补(BiFC)、酵母双杂交和qRT-PCR检测等一系列分析,以探究BnaCIPK15蛋白在ABA激素响应中的作用。结果显示:(1)亚细胞定位发现,BnaCIPK15蛋白定位于细胞质和细胞核中; BiFC分析发现,BnaCIPK15蛋白与BnaCBL1/3/4/9蛋白之间的互作较强,与BnaCBL10仅有微弱互作。(2)qRT-PCR检测发现,BnaCIPK15基因受ABA和冷胁迫的诱导极显著上调表达,而对百草枯(Paraquat)、活性氧(H_2O_2)和热胁迫的诱导较弱,表明BnaCIPK15基因很可能参与ABA和冷胁迫的调控过程。(3)酵母滴定实验结果显示,BnaCIPK15蛋白与脱落酸(ABA)信号通路中的BnaHAB1蛋白(属于蛋白磷酸酶PP2C家族)存在明显的互作,而与BnaABFs/AREB3/ABI5转录因子无明显互作;BiFC验证显示,BnaCIPK15与BnaHAB1蛋白之间存在互作信号,而BnaCIPK15与BnaHAB2组合没有观察到信号,证明BnaCIPK15与BnaHAB1磷酸酶具有特异互作特征,推测BnaCIPK15可能参与调控ABA信号转导。研究认为,甘蓝型油菜中可能存在基于BnaCIPK15-BnaHAB1的互作模块,并参与ABA的信号转导和网络调控。     

Integrative analyses of transcriptome and carotenoids profiling revealed molecular insight into variations in fruits color of Citrus Reticulata Blanco induced by transplantation

Citrus fruits exhibit vivid color and are favored extensively. However, the biochemical and molecular mechanism of Citrus Reticulata Blanco fruits coloring, especially the effect of transplantation on fruits coloring, is unclear. Herein, RNA-Seq and carotenoids profiling were applied to investigate the effect of transplantation on Orah mandarin fruits coloring. Transplantation induces fruit color shallowing, Ca²⁺ and ACC level declining and IAA level increasing. Transplantation induced variation in fruit skin and pulp carotenoids, mainly β-citraurin as one of the important pigments of citrus peel. 2253 up-regulated genes, 1103 down-regulated genes in skin and 815 up-regulated genes, 534 down-regulated genes in pulp of transplanted tree fruits were identified by RNA-Seq. The DEGs involved hormone signal, carotenoids biosynthesis and TFs such as MYB and bHLH family TFs. The carotenoid cleavage dioxygenase gene (Ciclev10028113m.g) is positively correlated with β-citraurin and regulated directly and/or indirectly by MYB1R1, PIF4, ACC and IAA. Integrative analyses revealed potential molecular insights into Orah mandarin peel color variation during transplantation.