Institute of Crop Sciences, National Engineering Laboratory of Crop Molecular Breeding, Chinese Academy of Agricultural Sciences, National Centre of Space Mutagenesis for Crop Improvement, Beijing, 100081, China.
Key Laboratory of Molecular Medicine and Biotherapy, School of Life Sciences, Beijing Institute of Technology, Beijing, 100081, China.
BMC Plant Biol. 2023 Aug 1;23(1):377. doi: 10.1186/s12870-023-04389-3.
Induction of mutation through chemical mutagenesis is a novel approach for preparing diverse germplasm. Introduction of functional alleles in the starch biosynthetic genes help in the improvement of the quality and yield of cereals.
In the present study, a set of 350 stable mutant lines were used to evaluate dynamic variation of the total starch contents. A megazyme kits were used for measuring the total starch content, resistant starch, amylose, and amylopectin content. Analysis of variance showed significant variation (p < 0.05) in starch content within the population. Furthermore, two high starch mutants (JE0173 and JE0218) and two low starch mutants (JE0089 and JE0418) were selected for studying different traits. A multiple comparison test showed that significant variation in all physiological and morphological traits, with respect to the parent variety (J411) in 2019-2020 and 2020-2021. The quantitative expression of starch metabolic genes revealed that eleven genes of JE0173 and twelve genes of JE0218 had consistent expression in high starch mutant lines. Similarly, in low starch mutant lines, eleven genes of JE0089 and thirteen genes of JE0418 had consistent expression in all stages of seed development. An additional two candidate genes showed over-expression (PHO1, PUL) in the high starch mutant lines, indicating that other starch metabolic genes may also contribute to the starch biosynthesis. The overexpression of SSII, SSIII and SBEI in JE0173 may be due to presence of missense mutations in these genes and SSI also showed overexpression which may be due to 3-primer_UTR variant. These mutations can affect the other starch related genes and help to increase the starch content in this mutant line (JE0173).
This study screened a large scale of mutant population and identified mutants, could provide useful genetic resources for the study of starch biosynthesis and genetic improvement of wheat in the future. Further study will help to understand new genes which are responsible for the fluctuation of total starch.
通过化学诱变诱导突变是制备多样化种质资源的一种新方法。在淀粉生物合成基因中引入功能等位基因有助于提高谷物的品质和产量。
本研究使用一组 350 个稳定的突变体系来评估总淀粉含量的动态变化。使用 megazyme 试剂盒测量总淀粉含量、抗性淀粉、直链淀粉和支链淀粉含量。方差分析表明，群体内淀粉含量存在显著差异（p<0.05）。此外，选择了两个高淀粉突变体（JE0173 和 JE0218）和两个低淀粉突变体（JE0089 和 JE0418）来研究不同的性状。多重比较测试表明，与亲本品种（J411）相比，2019-2020 年和 2020-2021 年所有生理和形态性状均存在显著差异。淀粉代谢基因的定量表达表明，JE0173 的 11 个基因和 JE0218 的 12 个基因在高淀粉突变体系中表达一致。同样，在低淀粉突变体系中，JE0089 的 11 个基因和 JE0418 的 13 个基因在种子发育的所有阶段都表现出一致的表达。另外两个候选基因在高淀粉突变体系中表现出过表达（PHO1、PUL），表明其他淀粉代谢基因也可能有助于淀粉生物合成。JE0173 中 SSII、SSIII 和 SBEI 的过表达可能是由于这些基因存在错义突变，而 SSI 也表现出过表达，这可能是由于 3-prime_UTR 变异。这些突变可能会影响其他与淀粉相关的基因，并有助于增加该突变体系（JE0173）中的淀粉含量。
本研究筛选了大规模的突变体群体，并鉴定了突变体，可为今后研究淀粉生物合成和小麦遗传改良提供有用的遗传资源。进一步的研究将有助于了解负责总淀粉波动的新基因。
