The Persimmon 9- XXXX Gene DkLOX3 Plays Positive Roles in Both Promoting Senescence and Enhancing Tolerance to Abiotic Stress.

@entity5568 @entity68796 @entity71873 @entity958 @entity26 @entity72855 @entity1234 @entity523 @entity72854 @entity3612 @entity544 @entity14319 @entity47392 @entity22715 @entity45325 @entity22714 @entity1865 @entity1786
The @entity71873 ( @entity71873 ) pathway is a key regulator for lipid peroxidation, which is crucial for plant senescence and defense pathways. In this study, the transcriptional expression patterns of three persimmon (Diospyros kaki L. 'Fupingjianshi') 9- @entity71873 genes (DkLOX1, DkLOX3, and DkLOX4) were investigated. DkLOX1 was specifically expressed in fruit, particularly in young fruit, and showed little response to the postharvest environments. DkLOX4 was expressed in all tissues and slightly stimulated by mechanical damage and low temperature. DkLOX3 was expressed mainly in mature fruit, and the expression was extremely high throughout the storage period, apparently up-regulated by mechanical damage and high @entity544 treatments. Further functional analysis showed that overexpression of DkLOX3 in @entity523 ( @entity523 cv. Micro-Tom) accelerated fruit ripening and softening. This was accompanied by higher @entity1234 ( @entity1865 ) content and @entity14319 accumulation, advanced @entity1786 release peak and elevated expression of @entity1786 synthesis genes, including @entity45325 , @entity68796 , and @entity72854 . In addition, DkLOX3 overexpression promoted dark induced transgenic @entity958 leaf senescence with more chlorophyll loss, increased electrolyte leakage and @entity1865 content. Furthermore, the functions of DkLOX3 in response to abiotic stresses, including osmotic stress, high salinity and drought were investigated. @entity958 DkLOX3 overexpression (DkLOX3-OX) transgenic lines were found to be more tolerant to osmotic stress with higher germination rate and root growth than wild-type. Moreover, DkLOX3-OX @entity958 plants also exhibited enhanced resistance to high salinity and drought, with similar decreased @entity3612 and @entity5568 accumulation and upregulation of stress-responsive genes expression, including @entity22714 , RD29A, @entity22715 , and @entity47392 , except for @entity72855 , which plays a negative role in stress response. Overall, these results suggested that DkLOX3 plays positive roles both in promoting ripening and senescence through lipid peroxidation and accelerated @entity1786 production and in stress response via regulating reactive @entity26 species accumulation and stress responsive genes expression.
