To date, most of the known functions of miR172 were determined in annual herbaceous plants. The miR172 was shown to have the lowest abundance in seedlings and increased during the juvenile-to-adult transition in several perennial trees. Although the microRNAs in Euphorbiaceae plants including Jatropha were isolated and compared, the functions of these microRNAs remain unknown.
Prof. XU Zengfu and his team of Xishuangbanna Tropical Botanical Garden（XTBG）analyzed the expression profiles of Jatropha miR172 (JcmiR172). They further characterized the function of JcmiR172a in leaf morphology, flowering induction, floral organ specification, and fruit and seed morphologies using transgenic Arabidopsis and Jatropha.
They found that miR172 is an age marker gene in Jatropha, which is similar to its role in other plants. The miR172 has conservative functions in regulating phase change, controlling leaf morphologies, and sustaining normal flower development .The functions of miR172 are different between annual herbaceous plants and perennial woody plants
They further found that the overexpression of miR172 shortened the juvenile stage in Jatropha. The miR172 cannot promote flowering independently; it also depends on suitable environmental conditions.
They then found elevated age markers of Jatropha by constitutive overexpression of JcmiR172a, which accelerated the lignification of the secondary xylem by indirectly promoting lignin biosynthesis and the expression of cellulose synthase gene.
“In particular, we found that miR172 plays a role in regulating xylem development in both Arabidopsis and Jatropha”, said Prof. XU Zengfu, principal investigator of the study.
The study entitled “miR172 Regulates both Vegetative and Reproductive Development in the Perennial Woody Plant Jatropha curcas” has been published in Plant and Cell Physiology.
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
Leaf and stem phenotypes of 35S: JcmiR172a transgenic Jatropha.
(Images by TANG Mingyong)
