文献类型： 外文期刊

作者： Yu, Jing ¹ ; Lei, Bo ² ; Zhao, Huina ² ; Wang, Bing ² ; Kakar, Kaleem U. ³ ; Guo, Yushuang ² ; Zhang, Xiaolian ¹ ; Jia, Mengao ² ; Yang, Hui ² ; Zhao, Degang ¹ ;

作者机构： 1.Guizhou Univ, Inst Agrobioengn, Coll Life Sci, Key Lab Plant Resources Conservat & Germplasm Inno, Guiyang, Peoples R China

2.Guizhou Acad Tobacco Sci, Mol Genet Key Lab China Tobacco, Guiyang, Peoples R China

3.Baluchistan Univ Informat Technol & Managemnet Sci, Dept Microbiol, Quetta, Pakistan

4.Guizhou Acad Agr Sci, Plant Conservat Technol Ctr, Guizhou Key Lab Agr Biotechnol, Guiyang, Peoples R China

关键词： NtMYB306a; transcription factors; trichomes; Nicotiana tabacum; alkane biosynthesis

期刊名称：FRONTIERS IN PLANT SCIENCE （ 影响因子：6.627； 五年影响因子：7.255 ）

ISSN： 1664-462X

年卷期： 2022 年 13 卷

页码：

收录情况： SCI

摘要： Trichomes are specialized hair-like organs found on epidermal cells of many terrestrial plants, which protect plant from excessive transpiration and numerous abiotic and biotic stresses. However, the genetic basis and underlying mechanisms are largely unknown in Nicotiana tabacum (common tobacco), an established model system for genetic engineering and plant breeding. In present study, we identified, cloned and characterized an unknown function transcription factor NtMYB306a from tobacco cultivar K326 trichomes. Results obtained from sequence phylogenetic tree analysis showed that NtMYB306a-encoded protein belonged to S1 subgroup of the plants' R2R3-MYB transcription factors (TFs). Observation of the green fluorescent signals from NtMYB306a-GFP fusion protein construct exhibited that NtMYB306a was localized in nucleus. In yeast transactivation assays, the transformed yeast containing pGBKT7-NtMYB306a construct was able to grow on SD/-Trp-Ade+X-alpha-gal selection media, signifying that NtMYB306a exhibits transcriptional activation activity. Results from qRT-PCR, in-situ hybridization and GUS staining of transgenic tobacco plants revealed that NtMYB306a is primarily expressed in tobacco trichomes, especially tall glandular trichomes (TGTs) and short glandular trichomes (SGTs). RNA sequencing (RNA-seq) and qRT-PCR analysis of the NtMYB306a-overexpressing transgenic tobacco line revealed that NtMYB306a activated the expression of a set of key target genes which were associated with wax alkane biosynthesis. Gas Chromatography-Mass Spectrometry (GC-MS) exhibited that the total alkane contents and the contents of n-C28, n-C29, n-C31, and ai-C31 alkanes in leaf exudates of NtMYB306a-OE lines (OE-3, OE-13, and OE-20) were significantly greater when compared to WT. Besides, the promoter region of NtMYB306a contained numerous stress-responsive cis-acting elements, and their differential expression towards salicylic acid and cold stress treatments reflected their roles in signal transduction and cold-stress tolerance. Together, these results suggest that NtMYB306a is necessarily a positive regulator of alkane metabolism in tobacco trichomes that does not affect the number and morphology of tobacco trichomes, and that it can be used as a candidate gene for improving stress resistance and the quality of tobacco.