As one of the world's most important food crops, wheat meets 20% of human calorie and protein needs and provides an energy source for more than a third of the world's population. Affected by extreme weather conditions and the international situation, several major exporters have cut production this year. According to fao data, wheat export prices have risen by 46% this year, global food prices have risen to a 10-year high, next year wheat prices will continue to soar and exacerbate global food inflation, increasing wheat production is a major issue directly related to world food security. Wheat yield is influenced by three main factors: panicle number per unit area, grain weight and grain per panicle, of which the number of panicles per unit area is affected by tillers, and the number of grains per panicle is determined by the number of paniclelets (SNS) and the number of earslets.
Recently, the Wheat Molecular Genetics Laboratory of Oklahoma State University cloned a CONSTANS-like family gene, TaCOL-B5, which has obvious regulatory effects on the number of spikelets, tillers and yield per plant, and field yield measurements show that this gene has a significant role in promoting wheat yield. The study was published online in Science on April 8 under the title "TaCol-B5 modifies spike architecture and enhances grain yield in wheat."
Figure 1 A's main effect QTL QSns.osu-7B, which regulates the development of spikelets, was localized on the Chr7B chromosome of wheat; B was screened by molecular markers to obtain four key recombinant plants (F5 generations); C-F P11-58, P19-236, P11-63 and P19-1121 F6 recombinant lines were separated from the small spike number (SNS) phenotype.
In a previous study, the laboratory constructed an F2 generation population by hybridization of CItr 17600 and Yangmai 18 cultivars, and identified a principal QTL (QSns.osu-7B) on chromosome Chr7B using the method of pattern cloning, which was able to explain 43% of the SNS phenotypic separations in the population (Figure 1A). To clone the gene, the lab screened four key recombinant plants from 1857 F5 generations and confined the candidate genes to a region of approximately 318,786 bp based on SNS isolation of their offspring. Two candidate genes are present in this region: TraesCS7B02G400600 and TraesCS7B02G400700 (Figure 1B). Sequence analysis showed that there were no sequence differences between the TraesCS7B02G400700 gene coding region and its possible promoter region between the two parents, but the TraesCS7B02G400600 gene coding region had multiple SNP loci between the two parents, and it was speculated that the gene was involved in the regulation of SNS traits. Since TradeSCS7B02G400600 encodes a CONSTANS-like protein, homologous to the COL5 gene in plants, it is named TaCOL-B5. To verify its function, the laboratory obtained four independent transgenic plants after overexpressing its dominant allele TaCol-B5 by transgenic technique, and then planted the offspring transgenic lines under greenhouse and field conditions and found that overexpression of the gene could increase the number of spikelets and panicle length, which significantly promoted wheat grain yield (Figure 1C).
Figure 2 There were significant phenotypic differences between non-transgenic plants and TaCol-B5 overexpressed strains under greenhouse conditions, and there were significant differences in SNS phenotype (B) and grain per panicle (C) between non-transgenic plants and TaCol-B5 overexpressed plants under greenhouse conditions, and there were significant phenotypic differences between T2-generation TaCol-B5 overexpressed lines and non-transgenic plants under D field conditions, and there were significant differences in SNS (E), panicle length (F), grain number per panicle (G) and panicle number per plant (H) under field conditions The phenotypic differences between T3-generation TaCol-B5 overexpressed lines and non-transgenic plants under I-J field conditions were still very obvious.
To validate this finding, the laboratory planted transgenic lines under field conditions for two consecutive years to verify yield trait-related phenotypes (Figure 2). The results showed that the yield of the four TaCol-B5 overexpressed strains of Yangmai 18 increased by an average of 11.9% compared with that of non-GMO Yangmai 18, and the yield of the most significant yield increase was 19.8%. Among the previous cloned wheat yield trait-related genes, no single gene has such a significant effect on panicle development and grain yield.
Fig. 3A yeast double heterozygotic verification of the obvious allele allele TaCol-B5 and TaK4 have interactions; there are three amino acid sites differences in the amino acid sequences of B TaCol-B5 and Tacol-B5, and the red part is the site that may be phosphorylated; C phosphorylation experiments prove that TaCol-B5 can be phosphorylated by TaK4.
The lab further found that TaCol-B5 is activated by phosphorylation of the serine/threonine protein kinase TaK4, and that Ser269 of TaCol-B5 is the phosphorylation site of TaK4 action (Figure 3), which is the first time TaK4 phosphokinase has been found to regulate spike development and yield traits. The laboratory also performed base knockout of the Tacol-B5 functional domain by gene editing, and introduced 1 base and 7 base deletion mutations in the CCT functional domains of the two successfully edited plants, Tacol-B5-ED1 and Tacol-B5-ED12, respectively. Under greenhouse conditions, the T1 generation base knockout lines of Tacol-B5-ED1 and Tacol-B5-ED12 showed the characteristics of flowering delay and plant height reduction compared with the control, and this phenotype further verified the function of TaCol-B5.
Fig. 4 Base knockout of Tacol-B5 by gene editing, introducing 1 base and 7 base deletion mutations (A and B) in the two successfully edited plants, respectively; compared with the control, the two base deletion strains differed significantly in flowering stage (C and D) and plant height (E and F); and different CCT protein family structure comparisons (G and H) were significantly different.
TaCol-B5 is a dominant allele produced by natural mutations that appear very infrequently in common wheat varieties currently grown worldwide, which is one of the reasons why the gene is so difficult to detect. The discovery of this gene is of landmark significance for the in-depth understanding of the mechanism of action of wheat yield trait genes, which has given us a deeper understanding of the mechanism of wheat yield increase.
Professor Liuling Yan and Professor Brett F. Carver of the Wheat Molecular Genetics Laboratory at Oklahoma State University are the corresponding authors. The first authors include Dr. Zhang Xiaoyu, a graduate of the laboratory (currently working at the Southern Economic Crops Research Center of the Institute of Hemp Sciences of the Chinese Academy of Agricultural Sciences), Professor Jia Haiyan (currently working in the College of Agronomy, Nanjing Agricultural University), and Associate Researcher Li Tian (currently working at the Institute of Crop Sciences, Chinese Academy of Agricultural Sciences).
Original link:
https://www.science.org/doi/10.1126/science.abm0717
Scientific research services (cooperative investment)
Patent Application | Rapid Detection of Transgenic Plants| Tissue Culture| Yeast Double Hybrid | Rice Mutant Library| Plant Genetic Transformation, Vector Construction, BIFC, RACE, Subcellular Localization, Genome Editing | Genetics technical services, SNP typing, high homologous segment SNP typing, target interval resequencing, methylation sequencing | Plant antibodies |
The forefront of plant science, focusing on the frontier progress of plant science, information, the release of recruitment information and method software sharing. For submission and recruitment, please reply to the "submission" in the background, all of which are free; for business cooperation, please contact WeChat ID: zwkxqy;