Four genes encoding MYB28, a major transcriptional regulator of the aliphatic glucosinolate pathway, are differentially expressed in the allopolyploid Brassica juncea.
Four genes encoding MYB28, a major transcriptional regulator of the aliphatic glucosinolate pathway, are differentially expressed in the allopolyploid Brassica juncea.
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DOI：
10.1093/jxb/ert280
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发表时间：
2013-11
影响因子：
6.9
通讯作者：
Bisht NC
中科院分区：
文献类型：
--
作者：
Augustine R;Majee M;Gershenzon J;Bisht NC
硫代葡萄糖苷是辣椒特有的次生代谢物，在人类健康和农业方面具有巨大的潜力。与拟南芥不同，我们对芥子油苷调节因子的了解很少。本研究从芥菜多倍体中鉴定出4个MYB28同源基因（BjuMYB28-1、-2、-3、-4），并分析了异源多倍体化对基因序列、结构、功能和表达差异的影响。4个BjuMYB28基因的蛋白序列与拟南芥MYB28的同源性为76.1-83.1%。系统发育分析表明，4个BjuMYB28蛋白通过杂交和复制过程进化形成了B. rapa （AA）和B. nigra （BB）的juncea基因组（AABB），同时保持了高度的序列保守性。在拟南芥中的突变体互补和过表达研究表明，所有4个BjuMYB28基因编码功能性MYB28蛋白，并导致相似的脂肪族硫代葡萄糖苷组成和含量。利用qRT-PCR和启动子gus细胞系对BjuMYB28基因进行了详细的表达分析，结果表明BjuMYB28基因在芥菜中具有组织特异性和细胞特异性的表达分配。两个来自b基因组的基因BjuMYB28在植物发育的早期阶段比a基因组的基因转录量更丰富。然而，随着生殖期的开始，所有四种BjuMYB28的表达水平都显著增加，这可能是在植物发育后期产生和维持大量脂肪族硫代葡萄糖苷所必需的。综上所述，我们的研究结果表明，4个MYB28基因在芥菜中差异表达和调控，在控制脂肪族硫代葡萄糖苷生物合成中发挥离散但重叠的作用。
Glucosinolates are Capparales-specific secondary metabolites that have immense potential in human health and agriculture. Unlike Arabidopsis thaliana, our knowledge about glucosinolate regulators in the Brassica crops is sparse. In the current study, four MYB28 homologues were identified (BjuMYB28-1,-2,-3,-4) from the polyploid Brassica juncea, and the effects of allopolyploidization on the divergence of gene sequence, structure, function, and expression were assessed. The deduced protein sequences of the four BjuMYB28 genes showed 76.1–83.1% identity with the Arabidopsis MYB28. Phylogenetic analysis revealed that the four BjuMYB28 proteins have evolved via the hybridization and duplication processes forming the B. juncea genome (AABB) from B. rapa (AA) and B. nigra (BB), while retaining high levels of sequence conservation. Mutant complementation and over-expression studies in A. thaliana showed that all four BjuMYB28 genes encode functional MYB28 proteins and resulted in similar aliphatic glucosinolate composition and content. Detailed expression analysis using qRT-PCR assays and promoter-GUS lines revealed that the BjuMYB28 genes have both tissue- and cell-specific expression partitioning in B. juncea. The two B-genome origin BjuMYB28 genes had more abundant transcripts during the early stages of plant development than the A-genome origin genes. However, with the onset of the reproductive phase, expression levels of all four BjuMYB28 increased significantly, which may be necessary for producing and maintaining high amounts of aliphatic glucosinolates during the later stages of plant development. Taken together, our results suggest that the four MYB28 genes are differentially expressed and regulated in B. juncea to play discrete though overlapping roles in controlling aliphatic glucosinolate biosynthesis.
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影响因子：
9.4
作者：
Gigolashvili, Tamara;Engqvist, Martin;Fluegge, Ulf-Ingo
通讯作者：
Fluegge, Ulf-Ingo
影响因子：
7.4
作者：
Celenza, JL;Quiel, JA;Bender, J
通讯作者：
Bender, J
影响因子：
13.8
作者：
Augustine, Rehna;Mukhopadhyay, Arundhati;Bisht, Naveen C.
通讯作者：
Bisht, Naveen C.
影响因子：
3.1
作者：
Howell, PM;Sharpe, AG;Lydiate, DJ
通讯作者：
Lydiate, DJ
影响因子：
7.2
作者：
Gigolashvili, Tamara;Berger, Bettina;Fluegge, Ulf-Ingo
通讯作者：
Fluegge, Ulf-Ingo