The Dynamic Changes In Endogenesis Hormone During Eggplant Parthenocarpic Fruit Development And Analysis Of Differentially Expressed Genes

Eggplant is a warm-season vegetable. In off-season and spring early maturing culture, the failure ofpollination and fertilization, flower drop and fruit drop that caused by low temperature often lead toreduced production efficiency. Eggplant parthenocarpy can partly conquer flower and fruit drop causedby low temperature, enhance the fruit setting rate, increase yield, improve fruit qualities and raisebenefit. Hence, it is of great importance to study eggplant parthenocarpy.In order to investigate the relationship between contents of endogenous plant hormones in ovary（fruit） and eggplant parthenocarpy, the parthenocarpic line D-10, D-21and non-parthenocarpic line03-2were examined at different stages of ovary （fruit）. The other aim of this research is to analyse thedifferentially expressed genes based on SSH library. The main results were summed as follows:1. The tendency of IAA、ZR and ABA contents in fruit development were similar after naturalpollination and artificial pollination among different temperature conditions. IAA、ZR and ABAcontents increased firstly, reached peak in the early stage of fruit development and then decreased.2. After natural pollination IAA and ABA contents in parthenocarpic line were higher than that innon-parthenocarpic line at early stage of fruit development which indicated that higher IAA andABA contents were beneficial to eggplant fruit development and parthenocarpy. There were noobvious difference in GA₄contents between natural pollination and artificial pollination. The effectof pollination methods on ZR content was complicated. GA₄and ZR may have little relationship toeggplant parthenocary.3. The changing trend of ABA/（IAA+GA₄+ZR） in fruit development was consistent with that ofABA. ABA/（IAA+GA₄+ZR） in parthenocarpic lines was obviously higher than that innon-parthenocarpy03-2line around flowering. ABA/（IAA+GA₄+ZR） in fruit development of03-2was always maintained on low level.4. Low temperature minimally affected IAA content of parthenocarpic line in the early stage of fruitdevelopment, but significantly decreased IAA content of non-parthenocarpic line03-2. No evidentregularity was found in the effects of temperature on GA₄contents in fruit development. Theeffects of temperature on ZR and ABA contents were behaved at early stage of fruit development.ZR synthesis around flowering was blocked by low temperature, whereas ABA content wasincreased significantly.5. Polyamines levels were higher at early stage of fruit development. The levels of polyamines,putrescine and spermidine increased firstly and then decreased. Spermine contents tended todecrease progressively. Putrescine levels were higher than spermine and spermidine levels.Putrescine and spermidine were beneficial to fruit development and parthenocarpy of eggplant.Spermidine may have little relationship to eggplant parthenocarpy.6. Fluorescent quantitative PCR was used to detected the different expression of109ESTs in ovary（fruit）development between parthenocarpic line D-10and non-parthenocarpic line03-2. The results showed that21ESTs were up-regulated in D-10, and28ESTs were down-regulated in D-10.There were many differentially expressed ESTs that related to plant hormones signal transduction.The difference in plant hormones between parthenocarpic line D-10and non-parthenocarpic line03-2may be regulated by differentially expressed ESTs.