Phytohormones are the major determinants in controlling axillary bud outgrowth. The identification of the hormone-responsive genes that are associated with bud dormancy and outgrowth could provide insight into the regulation of axillary bud growth. High-throughput sequencing is an effective method to identify the candidate genes or pathways involved in the regulation of different biological processes at the transcriptome level.

Prof. XU Zengfu and his team of Xishuangbanna Tropical Botanical Garden (XTBG) performed transcriptome analyses of the nodal stem after mock, GA3 gibberellin 3（GA3）and 6-benzyladenine (BA) treatments. They aimed to advance the current understanding of how the young axillary buds respond to exogenously applied GA3 or BA in Jatropha curcas.

RNA-seq transcriptome expression analysis was used to elucidate the mechanisms underlying bud outgrowth control and identify the potential genes involved in the regulation of bud outgrowth. Both BA and GA3 could directly promote bud outgrowth in J. curcas.

To further elucidate how the axillary bud responds to hormones and regulatory pathways in J. curcas, they identified the differentially expressed genes (DEGs) after GA3 or BA treatment using transcriptome sequencing.

Overall, 250 DEGs (fold-change ≥ 2, FDR < 0.05) were co-regulated in response to GA3 or BA treatment and also exhibited similar expression patterns.

The results suggested that GA3 and BA synergistically regulated axillary bud outgrowth in J. curcas.

Moreover, BA treatment may promote GA accumulation in the young axillary buds as a result of the up-regulation of GA biosynthesis genes and the down-regulation of GA degradation genes in the axillary bud.

The study helped to elucidate the cooperative relationship between these two hormones in regulating axillary bud outgrowth in J. curcas.

The study entitled “Comparative transcriptome analysis of axillary buds in response to the shoot branching regulators gibberellin A3 and 6-benzyladenine in Jatropha curcas” has been published in Scientific Reports.

Contact

Prof. XU Zengfu Ph.D Principal Investigator
Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, Yunnan, China
E-mail: zfxu@xtbg.ac.cn
Tel: +86 691 8713051