Temperature effects on endogenous indole‐3‐acetic acid levels in leaves and stamens of the normal and male sterile ‘stamenless‐2′ mutant of tomato (Lycopersicon esculentum Mill.)

Abstract

ABSTRACTThe indole‐3‐acetic acid (IAA) concentration in leaves and stamens of the normal and a temperature‐sensitive male sterile ‘stamenless‐2′ (sl‐2/sl‐2) mutant of tomato (Lycopersicon esculentum Mill.), grown under three temperature conditions, was measured by gas chromatography — mass spectrometry — selected ion monitoring (GC‐MS‐SIM) and by enzyme‐linked immunosorbant assay (ELISA). At low (LTR, 18°C day/15°C night), intermediate (ITR, 23°C day/18°C night), and high temperatures (HTR, 28°C day/23°C night), the mutant leaves had approximately 10 to 20 times higher IAA concentrations, respectively, than the normal leaves under these temperature regimes. Similarly, the stamens of mutant flowers had approximately five and eight times higher IAA concentration at ITR and HTR, respectively, than the normal flowers. In the low temperature reverted mutant stamens, however, the level of IAA was similar to that in normal stamens. Also, with an increase in temperature, there was an increase in the level of IAA in the leaves and stamens of mutant plants. However, different temperatures had no appreciable effect on the IAA content of leaves and stamens of normal plants. It is suggested that the high IAA content in leaves and stamens of the stamenless‐2 mutant is one of the factors associated with male sterility and carpellization of stamens in this mutant.