Role of auxin in tomato flower organs and fruit during development under high temperature conditions
Tomatoes are a major horticultural crop worldwide and are produced for both fresh consumption and processing. Tomato crop yields are maximized in climates with moderate to high temperatures. Experimental evidence indicates that reduced fruit set at high temperatures results from inhibited pollen development, anther release and viability, which correlate with altered metabolism of the plant hormone auxin. Recent advances in auxin biology have identified auxin influx and efflux carriers, which determine auxin fate and transport within and between plant cells. However, these findings were shown mainly in Arabidopsis root and apical meristem systems, while much less is known about auxin transport and action within floral organs and during fruit development, particularly in other plants such as tomato. Furthermore, temperature-dependent effects on auxin synthesis and sensitivity have also been demonstrated in some species, and auxin has recently been shown to reverse negative effects of high temperature on male floral organs in barley and Arabidopsis. The objectives of this research are to 1) Identify auxin homeostasis components that function during normal flower organs development and during fruit set and maturation, 2) Identify the auxin derivatives that function in flower and fruit organs during development, 3) Elucidate the mechanism(s) in which abiotic stress, especially heat, affects auxin homeostasis in the flower and fruit organs, and 4) To alter of auxin homeostasis by changing auxin metabolism-related genes expression in flower and fruit organs. The immediate practical objective of this research is to develop agricultural/horticultural practices that will reduce or prevent crop yield losses and suggest the timing and application of growth regulators to improve tomato yields under high temperature. Ultimately, the results from this study can be used in conjunction with molecular assisted breeding to develop cultivars with enhanced auxin in flower organs and fruits which are required for normal development during heat stress.
Project member: M. Sc. Sarah Breitenbach
In collaboration with Hagai Yasuar (Volcani Center) and Asaph Aharoni (Weizmann Institute) in Israel the project has been funded by:
