NOTE: Does Overexpression of Tomato Fructokinase (LeFRK1) in Cotton Enhance Yield?

Abstract

Efforts to identify and introduce single genes that could maintain or increase cotton production in water-limited production settings have resulted in extremely limited success. The primary objective of this investigation was to test whether overexpression of the tomato fructokinase gene, LeFRK1, in field-grown cotton could improve fiber yield under variable growth conditions and contrasting irrigation levels in warm semi-arid environments characteristic of the Southern High Plains. A secondary goal was to determine whether a larger field-scale experiment might be justified based upon the results of this exploratory work. Cotton overexpressing LeFRK1 was field grown in small plots for three years under irrigation, contrasting irrigation levels, or without irrigation. Increased yield was found when comparing all LeFRK1 lines relative to that of the control line, though seasonal and plant-to-plant variability limited confidence in the extension of results to production scale. We hypothesized that yield improvements resulted from a suite of responses arising from increased availability of photosynthate at the leaf to the whole-plant level to developing fruits. The results suggested that LeFRK1 overexpression might be a viable approach to improving cotton yield in warm, semi-arid environments characteristic of the southwestern U.S. However, field trials under agronomically relevant systems and at agronomically relevant scales are needed to confirm these findings.