Characterization Of Panicle Development Mutant Sidts1 And Function Analysis Of Candidate Gene In Setaria Italica

Foxtail millet is one of important crops in China.Because of its high nutritional value,foxtail millet has caused wide public concern over the recent years.Meanwhile,foxtail millet has relatively small genome?⁵10Mb?,self-pollination,has a high collinearity with the rice genome,which has been proposed as an ideal model for crops research.In addition,foxtail millet is C₄ plant,the deepening research of foxtail millet has important significance for understanding the C₄ photosynthesis.The development of the spike has a direct effect on the yield and quality of the grain crops.Research on panicle development,especially about spike,are not only important for understanding the genetic and reproductive of plants,but also for improving grain yield and quality.Using EMS mutagen deal with the wild-type Yu1,we found a stable panicle development mutant and named as sidts1?degenerated top spike?.Compared with the wild-type Yu1,the sidts1 mutant exhibited tight-spikelet,short-thin-tip-panicle,gradually reduced spike from bottom to top which led to aberrant on the top of the panicle,but the seed becomes larger for the whole panicle.In the upper part of the panicle,it show a significant red color at the tip some of the branches.In general,the sidts1 mutant has degenerated and red top spike.In addition,the sidts1 mutant has a significant increase in Zn and Fe concentration of panicle compared with the wild-type Yu1.Genetic mapping of the mutant gene was performed using F₂ plants that were generated from a cross of sidts1 and SSR41.Genetic analysis showed that the F₂ population separate proportion of the normal plant and the mutants was 3:1,suggesting that the mutant character was controlled by a single recessive gene.By map-based cloning,the sidts1 mutant gene was mapped to chromosome 6 within a 137 kb genomic DNA region.Analyzing high-throughput genome sequencing dates,we identified the candidate gene SiDTS1 finally.SiDTS1 encodes a ZIP?Zinc/iron permease?domain whichrelated to the uptake and transport of metal elements Zn and Fe et al.The expression of SiDTS1 gene was assayed at the root,stem,leaf and panicle at the booting stage,but the expression level was the highest in the panicle.The subcellular location found that SiDTS1 functioned in vacuole membrane.Analysis of the members of the ZIP family in foxtail millet genome and qRT-PCR analysis revealed that there were 16 ZIP family genes in the foxtail millet,which were specific for tissue expression patterns.In this study,the effects of Zn²⁺ and Fe²⁺ transportation on the spike development of foxtail millet were studied by using sidts1 mutant as the research material,which provided the direction for the study of the spike development of cereal crops.