MYB transcription factors in plants

AccessScience ◽  
2015 ◽  
2021 ◽  
Vol 22 (7) ◽  
pp. 3560
Author(s):  
Ruixue Xiao ◽  
Chong Zhang ◽  
Xiaorui Guo ◽  
Hui Li ◽  
Hai Lu

The secondary wall is the main part of wood and is composed of cellulose, xylan, lignin, and small amounts of structural proteins and enzymes. Lignin molecules can interact directly or indirectly with cellulose, xylan and other polysaccharide molecules in the cell wall, increasing the mechanical strength and hydrophobicity of plant cells and tissues and facilitating the long-distance transportation of water in plants. MYBs (v-myb avian myeloblastosis viral oncogene homolog) belong to one of the largest superfamilies of transcription factors, the members of which regulate secondary cell-wall formation by promoting/inhibiting the biosynthesis of lignin, cellulose, and xylan. Among them, MYB46 and MYB83, which comprise the second layer of the main switch of secondary cell-wall biosynthesis, coordinate upstream and downstream secondary wall synthesis-related transcription factors. In addition, MYB transcription factors other than MYB46/83, as well as noncoding RNAs, hormones, and other factors, interact with one another to regulate the biosynthesis of the secondary wall. Here, we discuss the biosynthesis of secondary wall, classification and functions of MYB transcription factors and their regulation of lignin polymerization and secondary cell-wall formation during wood formation.


2020 ◽  
Author(s):  
Kaihui Zhai ◽  
Guangwu Zhao ◽  
Hongye Jiang ◽  
Caixia Sun ◽  
Jingyu Ren

Abstract Background MYB transcription factors are involved in many biological processes, including metabolism, development and responses to biotic and abiotic stresses. In our previous work, a new MYB transcription factor gene, ZmMYB59 was induced by deep sowing and down-regulated during maize seed germination via Real-Time PCR. However, there are few reports on seed germination regulated by MYB proteins and the functions of ZmMYB59 remain unknown. Results In this study, to examine its functions, Agrobacterium -mediated transformation was exploited to generate ZmMYB59 transgenic tobacco and rice. In T 2 generation transgenic tobacco, germination rate, germination index, vigor index and hypocotyl length were significantly decreased by 25.0~50.9%, 34.5~54.4%, 57.5~88.3% and 21.9~31.2% compared to wild-type (WT) lines. In T 2 generation transgenic rice, germination rate, germination index, vigor index and mesocotyl length were notably reduced by 39.1~53.8%, 51.4~71.4%, 52.5~74.0% and 28.3~41.5%, respectively. On this basis, relative physiological indicators were determined. The activities of catalase, peroxidase, superoxide dismutase, ascorbate peroxidase and proline content of transgenic lines were significantly lower than those of WT, suggesting that ZmMYB59 reduced their antioxidant capacity. As well, ZmMYB59 expression extremely inhibited the synthesis of gibberellin A1 (GA 1 ) and cytokinin (CTK), and promoted the synthesis of abscisic acid (ABA) concurrently, which implied that seed germination was repressed by ZmMYB59 in hormone levels. Furthermore, cell length and cell number of hypocotyl/mesocotyl in transgenic plants were notably decreased. Conclusions Taken together, it proposed that ZmMYB59 plays a negative regulation during seed germination in tobacco and rice, which also contributes to illuminate the molecular mechanisms regulated by MYB transcription factors.


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