Abstract

A wide variety of physiological responses, including most light responses, also are modulated by photoreceptor gene such as PHYB. Phytochrome B (PHYB) expression patterns may be significant in the daily regulation of plant physiology and indicate an unexpectedly intimate relationship between the components of the input pathway. The present study shows successful transformation and mRNA expression in Phytochrome B transformed CIM 482 cotton plants. Transgenic cotton plants expressing Phytochrome B mRNA have showed more than two times increase in relative leaf growth rate (RLGR) and photosynthetic rate, more than one time increase in Root Weight Ratio (RWR), nearly half time increase in Stem Weight Ratio (SWR). Higher Relative leaf Growth Rate led to improved physiology of cotton plants, which have ultimate effects in fruit size and number. From this study we come to conclusion that Phytochrome B plants have showed significant increase in number of bolls but significant decrease in height as compared to control cotton plants.

Key words: Phytochrome B, mRNA, cotton physiology.