Gene expression of ethylene biosynthesis and ethylene signaling involved in chilling injury of Hom Thong Banana

This research studied the expression of ethylene-related genes involved with chilling injury (CI) of Hom Thong banana. Bananas fruit were treated with 1-methylcyclopropene (M) or ethylene (E), or left untreated (control; C) before being stored at 7±1 °C for four and eight days, with subsequent transfer to 25±1 °C for three days. Bananas treated with E were resistant to CI and had normal ripening. In contrast, bananas fumigated with M were susceptible to CI and did not ripen. The ripening index (peel color, firmness, and TSS) was related to a high expression of MaACS1 and MaACO1 genes after storage, whereas the expression of these genes in bananas treated with M was not apparent. The MaERS3 gene in bananas treated with E was upregulated after transfer to 25±1 °C while the expression levels of MaCTR1 and MaEIL2 were significantly down-regulated at 7±1 °C after four days. These results indicated that ethylene induces CI tolerance in Hom Thong banana to by suppression MaCTR1 gene and inducing MaACS and MaACO genes.