Identification and validation of the wound and insect bite early inducible promoter from Arabidopsis thaliana

Expression dynamics and a loss-of-function of Arabidopsis RabC1 GTPase unveil its role in plant growth and seed development

Transcript isoform dynamics, spatiotemporal expression, and mutational analysis uncover that Arabidopsis RabC1 GTPase is required for root length, flowering time, seed size, and seed mucilage. Rab GTPases are crucial regulators for moving different molecules to their specific compartments according to the needs of the cell. In this work, we illustrate the role of RabC1 GTPase in Arabidopsis growth and seed development. We identify and analyze the expression pattern of three transcript isoforms of RabC1 in different development stages, along with their tissue-specific transcript abundance. The promoter activity of RabC1 using promoter-GUS fusion shows that it is widely expressed during the growth of Arabidopsis, particularly in seed tissues such as chalazal seed coat and chalazal endosperm. Lack of RabC1 function led to shorter roots, lesser biomass, delayed flowering, and sluggish plant development. The mutants had smaller seeds than the wildtype, less seed mass, and lower seed coat permeability. Developing seeds also revealed a smaller endosperm cavity and shorter integument cells. Additionally, we found that the knock-out mutant had downregulated expression of genes implicated in the transit of sugars and amino acids from maternal tissue to developing seed. The seeds of the loss-of-function mutant had reduced seed mucilage. All the observed mutant phenotypes were restored in the complemented lines confirming the function of RabC1 in seed development and plant growth.

Overview of Repressive miRNA Regulation by Short Tandem Target Mimic (STTM): Applications and Impact on Plant Biology

The application of miRNA mimic technology for silencing mature miRNA began in 2007. This technique originated from the discovery of the INDUCED BY PHOSPHATE STARVATION 1 (IPS1) gene, which was found to be a competitive mimic that prevents the cleavage of the targeted mRNA by miRNA inhibition at the post-transcriptional level. To date, various studies have been conducted to understand the molecular mimic mechanism and to improve the efficiency of this technology. As a result, several mimic tools have been developed: target mimicry (TM), short tandem target mimic (STTM), and molecular sponges (SPs). STTM is the most-developed tool due to its stability and effectiveness in decoying miRNA. This review discusses the application of STTM technology on the loss-of-function studies of miRNA and members from diverse plant species. A modified STTM approach for studying the function of miRNA with spatial-temporal expression under the control of specific promoters is further explored. STTM technology will enhance our understanding of the miRNA activity in plant-tissue-specific development and stress responses for applications in improving plant traits via miRNA regulation.