ECTOPIC EXPRESSION OF MPF2-LIKE PROTEIN WSA206 LEADS TO ARREST IN SILIQUE AND SEED DEVELOPMENT IN HETEROLOGOUS HOST

 

MUHAMMAD RAMZAN KHAN

 

National Centre for Bioinformatics, Quaid-i-Azam University, Islamabad, Pakistan

Previous address: National Institute for Genomics and Advanced Biotechnology (NIGAB), National Agricultural Research Centre, Park Road, Islamabad, Pakistan

Correspondenc: mrkhan@qau.edu.pk

 

Abstract

 

MPF2-like genes belonging to STMADS11 clade of MADS-box transcription factors are mostly involved in calyx inflation, floral reversion and fertility. However their role in fertility remained enigmatic. In this study we transformed WSA206 gene paralog - originated through genome duplication in a Solanaceous plant Withaniasomnifera - ectopically in a heterologous host Arabidopsis thaliana. Interesting phenotypes in floral organs and fruits were observed. Overexpression of WSA206 leads to arrest in silique development. The siliques were compressed and size was drastically reduced from 34mm to 3mm. Along with siliques, the seed development was also suppressed as revealed by shriveling of seeds and reduction in seed number. In extreme cases the siliques were devoid of any seeds. In cases where seeds developed, these were impaired in viability. Besides, the transgenic Arabidopsis also exhibited exorbitant growth of calyx to an extent that it resembled inflated calyx in Solanaceae. The calyx remained persistent and encapsulated the under-developed siliques containing non-viable seeds inside. Thus, fertility and sepal development are tightly coupled traits that are controlled by WSA206paralog in heterologous system.

 

Key words: MPF2-like, MADS-box, Expression, Arabidopsis, Fertility, Calyx, Withania