Ectopic expression of PmGRF7 isolated from Japanese apricot in tomato leads to seed sterility

The role of GRF (Growth-regulating Factor) in regulating plant growth and development has been studied, but its potential role in regulating seed fertility remains unclear. PmGRF7 overexpression in tomatoes altered leaf morphology and pollen activity. Most importantly, genetically modified tomato plants had no offspring. PmGRF7 overexpression resulted in abnormal leaf morphology, and transgenic plants that produced seedless fruit or seeds only showed signs of abortion. Pollination of genetically modified tomatoes with wild-type tomato pollen still produced sterile seeds. Further research using bioinformatics tools and physiological index measurement showed that PmGRF7 induced a hormone pathway leading to seed sterility, and at the same time, it caused differential genes to be induced in the plant hormone signal transduction pathway, ribosome pathway, sphingolipid metabolism and other related pathways, leading to morphogenesis in plant leaves. Collectively, our research findings reveal a potential new mechanism by which PmGRF7 regulates seed fertility and leaf growth, and these findings are of potential application in molecular plant breeding.