P SAG12 -IPT overexpression in eggplant delays leaf senescence and induces abiotic stress tolerance.

The isopentytransperase (IPT) gene, coupled to theSAG12promoter, was successfully transferred into the eggplant (Solanum melongenaL.) mediated byAgrobacterium tumefaciens. Four PSAG12IPT overexpressing transgenic plants were identified by Southern blotting. Reverse transcription polymerase chain reaction revealed thatIPTwas expressed in senescent leaves under the control ofSAG12promoter. Compared with wild type eggplants, the leaf senescence was significantly delayed and tolerance to drought and cold stress was enhanced in the T1generation of PSAG12-IPT transgenic eggplants. The contents of chlorophyll, indoleacetic acid, zeatin riboside, and gibberellic acid in the transgenic eggplants were higher than those in the wild type eggplants. The activities of reactive oxygen species-scavenging enzymes in the transgenic eggplants were also higher than those in the wild type eggplants. Abscisic acid and malondialdehyde levels were lower in the transgenic plants than in the wild type plants. Also the vegetative growth rate and yield of the transgenic plants were higher than those of the wild type eggplant. Our study suggests that the PSAG12-IPT expression cassette may be suitable for the genetic improvement of eggplant. [ABSTRACT FROM PUBLISHER]