Antisense-mediated depletion of tomato chloroplast glycerol-3-phosphate acyltransferase affects male fertility and increases thermal tolerance

A chloroplast-localized tomato (Lycopersicon esculentum Mill.) glycerol-3-phosphate acyltransferase (LeGPAT) gene was isolated. The antisense tomato plants were got under the control of the caulifower mosaic virus 35S promoter (35S-CaMV). RNA gel blot analysis confirmed that the expression of LeGPAT was inhibited in the tomato genome. The depletion of LeGPAT caused a massive arrest in pollen development. It also increased the size of tapetal cells, delayed tapetum degeneration, reduced ER membrane biogenesis and altered oil body size. Results therefore suggested that LeGPAT played a crucial role in pollen development. There was, however, no effect on the ovule. The depletion of LeGPAT also increased the saturation of phosphatidylglycerol (PG) fatty acids in thylakoid membranes. Increase of PG-saturated fatty acids was helpful in alleviating photoinhibition of PSII in tomato plants under heat stress.