miR172 Regulates both Vegetative and Reproductive Development in the Perennial Woody Plant Jatropha curcas

Abstract

Jatropha curcas is a promising feedstock for biofuel production because its oil is highly suitable for processing bio-jet fuels and biodiesel. However, Jatropha exhibits a long juvenile stage in subtropical areas. miR172, a conserved small non-protein-coding RNA molecule with 21 nucleotides, regulates a wide range of developmental processes. To date, however, no studies have examined the function of miR172 in Jatropha. There are five miR172 precursors encoding two mature miR172s in Jatropha, which are expressed in all tissues, with the highest expression level in leaves, and the levels are up-regulated with age. Overexpression of JcmiR172a resulted in early flowering, abnormal flowers, and altered leaf morphology in transgenic Arabidopsis and Jatropha. The expression levels of miR172 target genes were down-regulated, and the flower identity genes were up-regulated in the JcmiR172a-overexpressing transgenic plants. Interestingly, we showed that JcmiR172 might be involved in regulation of stem vascular development through manipulating the expression of cellulose and lignin biosynthesis genes. Overexpression of JcmiR172a enhanced xylem development and reduced phloem and pith development. This study helped elucidate the functions of miR172 in perennial plants, a known age-related miRNA involved in the regulation of perennial plant phase change and organ development.

MiR156 regulates anthocyanin biosynthesis through SPL targets and other microRNAs in poplar

“…Moreover, the transcript abundances of miR172-targeted AP2 s consistently increased in the transgenic plants. The function of the miR172- AP2 module in both vegetative and reproductive development has been studied in various woody plant species 35 . Taken together, our results suggest that other microRNA-target modules directly or indirectly regulated by miR156- SPL s could also affect poplar morphology.…”

Analysis of miRNA-mediated Regulation of Flowering Induction in Lilium × formolongi

“…There are ve miR172 family members and miR172b could be negatively regulated by miR156e to in uence the juvenile-adult phase change [31]. In the perennial species Jatropha curcas, only two miR172s have been identi ed [41]. However, ten miR172s and only one miR172 (miR172a) were identi ed among the differentially expressed miRNAs in our libraries.…”

Besides and beyond Flowering: Other Roles of EuAP2 Genes in Plant Development

“…[53] showed that hexuple-null mutant of Arabidopsis euAP2 genes phenocopied constitutively overexpressed miR172 in flowering time. Therefore, results obtained by [72,[75][76][77][78][79], from experiments where miR172 was constitutively overexpressed, are equivalent to the loss of function of entire euAP2 genes in the plant species studied.…”