Gene-Indexed Mutations in Maize.

Area of Science:

• Plant genetics
• Genomics
• Maize functional genomics

Background:

• The maize B73 reference genome enables large-scale gene characterization.
• Most maize genes lack functional characterization due to limited reverse genetic resources.

Purpose of the Study:

• To generate a comprehensive, gene-indexed mutant collection for high-throughput maize gene functional analysis.
• To facilitate the discovery of novel gene functions and desirable alleles for maize breeding.

Main Methods:

• Ethyl methanesulfonate (EMS) mutagenesis was employed to create mutations in maize.
• Exome capture and next-generation sequencing were used to detect and index mutations in 1086 M1 plants.
• Identification of point mutations (CG>TA) and InDel mutations across the maize genome.

Main Results:

• A total of 195,268 point mutations and 4,610 InDel mutations were identified.
• Mutations were found in 32,069 genes, representing 82% of all predicted protein-coding genes.
• An average of 180 mutations per line and 6.1 mutations per gene were detected, with 27,214 critical mutations (start/stop codon, missplice) in 14,101 genes.

Conclusions:

• The gene-indexed genome-wide mutation collection is a valuable resource for maize functional genomics.
• This resource enables efficient identification of genes with critical mutations, such as the ent-kaurene synthase gene involved in gibberellin biosynthesis.
• The collection holds potential for discovering desirable allelic variants to improve maize genetic breeding.