Fast neutron (FN) radiation mediated mutagenesis is a unique approach among the several induced mutagenesis methods being used in plant science in terms of impacted mutations. The FN mutagenesis usually creates deletions from few bases to several million bases (Mb). A library of random deletion generated using FN mutagenesis lines can provide indispensable resources for the reverse genetic approaches. In this review, information from several efforts made using FN mutagenesis has been compiled to understand the type of induced mutations, frequency, and genetic stability. Concerns regarding the utilization of FN mutagenesis technique for a plant with different level of ploidy and genome complexity are discussed. We have highlighted the utility of next-generation sequencing techniques that can be efficiently utilized for the characterization of mutant lines as well as for the mapping of causal mutations. Pros and cons of mapping by mutation (MutMap), mutant chromosome sequencing (MutChromSeq), exon capture, whole genome sequencing, MutRen-Seq, and different tilling approaches that can be used for the detection of FN-induced mutation has also been discussed. Genomic resources developed using the FN mutagenesis have been catalogued wooing to meaningful utilization of the available resources. The information provided here will be helpful for the efficient exploration for the crop improvement programs and for better understanding of genetic regulations.

Metacaspases (MCs), a class of cysteine-dependent proteases found in plants, fungi, and protozoa, are predominately involved in programmed cell death processes. In this study, we identified metacaspase genes in cultivated and wild rice species. Characterization of metacaspase genes identified both in cultivated subspecies of Oryza sativa, japonica, and indica and in nine wild rice species was performed. Extensive computational analysis was conducted to understand gene structures, phylogenetic relationships, cis-regulatory elements, expression patterns, and haplotypic variations. Further, the haplotyping study of metacaspase genes was conducted using the whole-genome resequencing data publicly available for 4726 diverse genotype and in-house resequencing data generated for north-east Indian rice lines. Sequence variations observed among wild and cultivated rice species for metacaspase genes were used to understand the duplication and neofunctionalization events. The expression profiles of metacaspase genes were analyzed using RNA-seq transcriptome profiling in rice during different developmental stages and stress conditions. Real-time quantitative PCR analysis of candidate metacaspase genes in rice cultivars Pusa Basmati-1 in response to Magnaporthe oryzae infection indicated a significant role in the disease resistance mechanism. The information provided here will help to understand the evolution of metacaspases and their role under stress conditions in rice.

Fast neutron (FN) radiation mediated mutagenesis is a unique approach among the several induced mutagenesis methods being used in plant science in terms of impacted mutations. The FN mutagenesis usually creates deletions from a few bases to several million bases (Mb). A library of random deletion generated using FN mutagenesis lines can provide indispensable resources for the reverse genetic approaches. In this review, information from several efforts made using FN mutagenesis has been compiled to understand the type of induced mutations, frequency, and genetic stability. Concerns regarding the utilization of FN mutagenesis technique for a plant with different level of ploidy and genome complexity are discussed. We have highlighted the utility of next-generation sequencing techniques which can be efficiently utilized for the characterization of mutant lines as well as for the mapping of causal mutations. Pros and cons of Mut-map, MutChromSeq, exon capture, whole genome sequencing, MutRen-Seq, and different tilling approaches can be used for the detection of FN-induced mutation has also been discussed. Genomic resources developed using the FN mutagenesis have been catalogued wooing to meaningful utilization of the available resources. The information provided here will be helpful for the efficient exploration for the crop improvement programs and for better understanding of genetic regulations.