Biological and genomic analysis of a symbiotic nitrogen fixation defective mutant in Medicago truncatula

Abstract

Medicago truncatula has been selected as one of the model legume species for gene functional studies. To elucidate the functions of the very large number of genes present in plant genomes, genetic mutant resources are very useful and necessary tools. Fast Neutron (FN) mutagenesis is effective in inducing deletion mutations in genomes of diverse species. Through this method, we have generated a large mutant resource in M. truncatula. This mutant resources have been used to screen for different mutant using a forward genetics methods. We have isolated and identified a large amount of symbiotic nitrogen fixation (SNF) deficiency mutants. Here, we describe the detail procedures that are being used to characterize symbiotic mutants in M. truncatula. In recent years, whole genome sequencing has been used to speed up and scale up the deletion identification in the mutant. Using this method, we have successfully isolated a SNF defective mutant FN007 and identified that it has a large segment deletion on chromosome 3. The causal deletion in the mutant was confirmed by tail PCR amplication and sequencing. Our results illustrate the utility of whole genome sequencing analysis in the characterization of FN induced deletion mutants for gene discovery and functional studies in the M. truncatula. It is expected to improve our understanding of molecular mechanisms underlying symbiotic nitrogen fixation in legume plants to a great extent.

Novel 4-Chromanone-Derived Compounds as Plant Immunity Inducers against CMV Disease in Passiflora spp. (Passion Fruit)

“…The transcriptome sequencing data were evaluated for a valid ratio, Q20 and Q30 base proportions, and GC content, with summarized results presented in Table 3 . Based on the findings from Table 3 , it can be concluded that the sequencing of both samples exhibited exceptional quality, with valid ratios > 98%, proportions of Q20 bases > 98%, proportions of Q30 bases > 93%, and GC contents > 43%, indicating suitability for a subsequent bioinformatics analysis [ 34 ].…”

Variation in a microbial mutualist has cascading consequences for host-parasite interactions

“…Of these 83 differentially expressed NCR genes, 54 responded to nematode infection status in at least one model, 63 responded to rhizobial strain differences in at least one model, 34 responded to both nematode infection status and rhizobial strain differences in at least one model, and 29 responded in a strain-specific manner (i.e., an infection ✕ rhizobia strain interaction). Three of the differentially expressed NCR protein genes (MtrunA17_Chr3g0083081, MtrunA17_Chr3g0083091, and MtrunA17_Chr3g0083111) are present in a region of chromosome 3 that causes defective nitrogen fixation when deleted (Shen et al, 2023) and all three had a response to rhizobial strain differences or nematode infection in at least one model.…”