JAZ (Jasmonate ZIM-domain) proteins are important repressors in JA signaling
pathway. JAZs take part in various developmental processes as well as in
resistance to biotic and abiotic stresses in Arabiodopsis. However, in
tomato, the studies on these JAZs are rare, especially on their roles in
plant growth and development. The research team of Xiaohui Yu from Chongqing
University in
<[www.isaaa.org]
s/download/Facts%20and%20Trends%20-%20China.pdf> China isolated and studied
a tomato JAZ gene, SlJAZ2.

Tomato plants overexpressing SlJAZ2 exhibited quicker leaf initiation,
reduced plant height and internode length. The transgenic tomatoes also had
decreasing trichomes, earlier lateral bud emergence and advanced flowering
transition. Further experiments showed that pith cells in transgenic plant
stems were much smaller than wildtypes as a result of the downregulation of
genes related to cell elongation and gibberellin synthesis.

Genes controlling trichome formation were also inhibited. Furthermore, there
was earlier flower initiation in transgenic plants, and the genes
controlling flowering time were upregulated significantly after SlJAZ2
overexpression.

These results suggest that SlJAZ2 could be related to the initiation of the
plants' reproductive stage as its overexpression accelerated the plants'
transition from vegetative to reproductive growth.

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