ANNOUNCEMENTS
Arabidopsis thaliana is a model organism and an important platform used to discover and test a variety of biological processes. The plant has five pairs of chromosomes with 135Mbp genome size. Arabidopsis itself is not agronomically important, but it helps us gaining sights into genetics and cell biology since the system has been well studied and resources are readily available. Agricultural sector is the major bread and butter for the country. Most of the gross domestic product comes from the primary sector. Improvement of crops is more of a necessity than just an area of research. Arabidopsis thaliana is a dicot and it belonging to the Brassicaceae family, which is shared by many important food crops, for example Mustard. Meiosis is a reductional division of the cell which includes mixing up the genetic information through recombination and segregation of chromosomes. A Single duplication event followed by two cycles of division is a characteristic trait of meiosis. Although a lot of research has been conducted in this area, a complete map of gene-regulatory networks and the genes they control is still lacking.The NAC domain proteins get their name from the NAM (no apical meristem), ATAF1 and 2 and CUC (cup shaped cotyledon) proteins. These domains have a wide range of functions from development to stress response. The expression and role of these genes in meiosis need to be haracterized. NAC domain is a family of transcription regulators that are present in plants exclusively. Recognizing the gap in the knowledge, herein we aim to characterize these NAC genes through mutations using CRISPR Cas9 since they are present in close proximity to each other and may be redundant in their function. They have a potential role in meiosis due to the observation that a class of NAC domains is expressed during meiosis and differential gene expression in certain meiosis defective mutants. The role of these domains in meiosis has not been characterized.NAC domains were mutated using CRISPR Cas9 which is a highly sequence specific gene editing molecular machinery. We attempted complete knock outs of the redundant sequences, but during the course of this study mutation for only 1 was obtained.The plants showed seed set reduction in the edited lines inT3 generation pointing towards the proof of the hypothesis. There was reduction in the number of seeds, CRISPR mutants were created.Cloning constructs for the NAC proteins were obtained for protein expression. Another parallel experiment is going on where we aim to silence a gene responsible for shoot meristem maintenance using miRNA in the background of a mutant copy gene that is required for meiotic progression Characterization of these transcription factors in meiosis may lead to economical application in crops.
Keywords: NAC domains, CRISPRCas9, meiosis, haracterization, A.thaliana
