Research Projects

The world’s population is consistently growing and is predicted to reach 9.5 billion by 2050, henceforth to satisfy the demand of food, fiber and oil, up to 70% increase in the present-day agricultural production is farsighted. The climate is also constantly changing, and the crop plants are largely suffering from stress conditions, thus leading to reduced annual yields. Therefore, to meet the food and cooking oil demand worldwide, a significant increase in the rate of mustard agricultural production is urgently needed. Brassica spp. is the economically important major oil crop worldwide, and the silique length directly influences seed yield in mustard. Several silique-related traits have been shown to be related to yield (i.e., siliques per plant, seeds per silique, and seed weight) and thus, are significant for mustard breeding. Therefore, longer siliques is always a desirable trait in mustard crop for high seed yield. Evidently, several genes and transcription factors were induced during early stages of mustard silique initiation and elongation. Many of these factors are the direct targets of microRNAs (miRNAs) that mediate target gene regulation by mRNA degradation or translational repression. In developing siliques, several differentially expressed including auxin signaling regulatory miR160/miR167 are observed to be important families targeting Auxin Response Factors (ARFs), the major class of hormone signaling genes that control silique length and number of seeds per silique (Chen et al., 2007). The ARF proteins are bound to the auxin response elements and regulate auxin-mediated transcriptional activation/repression in the cell. Therefore, to functionally characterize miR167 gene family in mustard, the target mimicry technology is proposed to be employed in Indian mustard B. juncea. It aims to analyse in vivo functions through target-mimicry-based expression diminution of auxin-signaling associated miR167 genes during slilique initiation, elongation and seed formation by generating transgenic stocks in B. juncea with (i) constitutive (CaMV35S promoter) overexpression of ‘miR167 precursor target-mimic sequence’ (ii) flower-specific (FSP046 promoter) overexpression of ‘miR167 precursor target-mimic sequence’ and (iii) constitutive (CaMV35S promoter) overexpression of native ‘miR167 sequence’. In result, the spatiotemporal overexpression (=in siliques) of ‘miR167 precursor target-mimic sequence’ and ‘native miRNA sequence’ will regulate hormone (auxin) with their reduced control on hormone signaling genes signaling during silique initiation, elongation and seed formation that may influence silique length and seed number per silique. Hence, the enhanced knowledge regarding miR167 genes at system and functional level will aid to our understanding for enhanced silique phenotypes, and hence, could be used for future mustard improvement programs.