Cloning and functional characterization of MusaVND1 using transgenic banana plants

Abstract

Vascular related NAC (NAM, ATAF and CUC) domain-containing genes regulate secondary wall deposition and differentiation of xylem vessel elements. MusaVND1 is an ortholog of Arabidopsis VND1 and contains the highly conserved NAC domain. The expression of MusaVND1 is highest in developing corm and during lignification conditions, the increase in expression of MusaVND1 coincides with the expression of PAL, COMT and C4H genes. MusaVND1 encodes a nuclear localized protein as MusaVND1-GFP fusion protein gets localized to nucleus. Transient overexpression of MusaVND1 converts banana embryogenic cells to xylem vessel elements, with a final differentiation frequency of 33.54% at the end of tenth day. Transgenic banana plants overexpressing MusaVND1 showed stunted growth and were characterized by PCR and Southern blot analysis. Transgenic banana plants showed transdifferentiation of various types of cells into xylem vessel elements and ectopic deposition of lignin in cells of various plant organs such as leaf and corm. Tracheary element formation was seen in the cortical region of transgenic corm as well as in epidermal cells of leaves. Biochemical analysis indicates significantly higher levels of lignin and cellulose content in transgenic banana lines than control plants. MusaVND1 overexpressing transgenic banana plants showed elevated expression levels of genes involved in lignin and cellulose biosynthesis pathway. Further expression of different MYB transcription factors positively regulating secondary wall deposition was also up regulated in MusaVND1 transgenic lines.

Banana fruit NAC transcription factor MaNAC5 cooperates with MaWRKYs to enhance the expression of pathogenesis‐related genes against Colletotrichum musae

“…Recently, genome-wide bioinformatics analysis has identified 167 potentially functional MaNAC genes in banana (Cenci et al, 2014), although their involvement in physiological processes is largely unknown. Banana MusaVND1, an orthologue of Arabidopsis VND1, regulates secondary wall deposition and differentiation of xylem vessel elements (Negi et al, 2015). In our previous studies, six banana NAC genes were characterized, and two, termed MaNAC1 and MaNAC2, were ripening and ET induced, and were involved in banana fruit ripening via interaction with the ET signalling pathway (Shan et al, 2012).…”

Banana NAC transcription factor MusaNAC042 is positively associated with drought and salinity tolerance

“…In the recent years, there has been growing interest on the characterization of the NAC transcription factors in banana with emphasis on secondary wall development and stress responses. MusaVND1, a banana NAC domain containing transcription factor was demonstrated to convert banana embryogenic cells into tracheary elementslike cells indicating its role in xylem development (Negi et al 2015a). Further, MusaVND2 and MusaVND3 were reported to exhibit ability to develop ectopic secondary wall development in transgenic banana (Negi et al 2015b).…”

The Effect of Pathogenesis-Related 10 (PR-10) Gene on the Progression of Fusarium Wilt in Musa acuminata cv. Berangan

“…We isolated PR-10 from the same plant species to minimize the biosafety concerns and to increase the likelihood of its acceptability to consumers. There is a noticeably growing number of publications in banana transgenic research utilizing banana-derived genes, particularly after the completion of the plant's whole genome sequencing (Negi et al 2014;Shekhawat & Ganapathi 2014;Sreedharan et al 2013). Embryogenic cell suspension (ECS) was chosen as the explant since the plantlets regenerated from ECS were reported to be of single cell origin thus minimizing the chimerism issues which is a general problem in transformation using other explants (Ghosh et al 2009).…”