Co-Authors:
Pressman, E., Department of Vegetable Research, Institute of Plant Sciences, Volcani Center, P.O. Box 6, Bet-Dagan 50250, Israel
Harel, D., Department of Vegetable Research, Institute of Plant Sciences, Volcani Center, P.O. Box 6, Bet-Dagan 50250, Israel
Zamski, E., Institute of Plant Sciences and Genetics, Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot 76100, Israel
Shaked, R., Department of Vegetable Research, Institute of Plant Sciences, Volcani Center, P.O. Box 6, Bet-Dagan 50250, Israel
Althan, L., Department of Vegetable Research, Institute of Plant Sciences, Volcani Center, P.O. Box 6, Bet-Dagan 50250, Israel
Rosenfeld, K., Department of Vegetable Research, Institute of Plant Sciences, Volcani Center, P.O. Box 6, Bet-Dagan 50250, Israel
Firon, N., Department of Vegetable Research, Institute of Plant Sciences, Volcani Center, P.O. Box 6, Bet-Dagan 50250, Israel
Abstract:
Exposure to high temperatures causes reduced yields in tomato (Lycopersicon esculentum), mainly by affecting male gametophyte development. The effect of heat stress on pollen characteristics is associated with changes in carbohydrate metabolism in the developing anthers. The expression and activities of sucrose-cleaving enzymes and the amounts of starch and soluble sugars were measured in tomato (inbred line 'NC 8288') anthers at four stages of development, under 'normal' controlled (day/night temperatures of 26°/18°C) and high-temperature (day/night temperatures of 32°/26°C) conditions. Heat stress was found to cause a reduction in cell wall-bound acid invertase activity in the anthers of flower buds 5 d before anthesis (DBA), which correlated with reduced starch accumulation at 3 DBA, and an induction of the activities of sucrose synthase and soluble acid invertase in maturing anthers. The heat stress-induced increases in soluble acid invertase and sucrose synthase activities close to anthesis were found to correlate with a three-fold increase in the hexose:sucrose ratio in mature anthers. The heat-stress conditions applied altered the gene expression profiles of the enzymes tested, decreasing the steady-state level of the mRNA coding for cell wall-bound acid invertase at 5 DBA, increasing expression of the soluble acid invertase gene at 5 DBA, and decreasing expression of the sucrose synthase gene at 5 and 3 DBA. These data indicate that sucrose-cleaving enzymes in tomato anthers respond, at both the mRNA and enzyme activity levels, to high-temperature conditions, that the response is dependent upon the stage of flower development, and that it may involve post-transcriptional control.
תפריט נגישות
ניגודיות עדינה
מונוכרום
הדגשת קישורים
חסימת אנימציה
פונט קריא
סגור
איפוס הגדרות נגישות
להורדת מודול נגישות חינם
