State Key Laboratory of Genetic Engineering, MOE Key Laboratory for Biodiversity Science and Ecological Engineering, MOE Engineering Research Center of Gene Technology, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China.
Institute of Metabolism and Integrative Biology, Fudan University, Shanghai, 200438, China.
Nat Commun. 2020 Dec 8;11(1):6266. doi: 10.1038/s41467-020-20133-z.
Grain weight (GW) is one of the component traits of wheat yield. Existing reports have shown that multiple phytohormones are involved in the regulation of GW in different crops. However, the potential role of jasmonic acid (JA) remains unclear. Here, we report that triticale grain weight 1 (tgw1) mutant, with marked reductions in both GW and JA content, is caused by a premature stop mutation in keto-acyl thiolase 2B (KAT-2B) involved in β-oxidation during JA synthesis. KAT-2B overexpression increases GW in wild type and boosts yield. Additionally, KAT-2B compliments the grain defect in tgw1 and rescues the lethal phenotype of the Arabidopsis kat2 mutant in a sucrose-free medium. Despite the suppression of JA synthesis in tgw1 mutant, ABA synthesis is upregulated, which is accompanied by enhanced expression of SAG3 and reduction of chlorophyll content in leaves. Together, these results demonstrate a role of the JA synthetic gene KAT-2B in controlling GW and its potential application value for wheat improvement.
粒重（GW）是小麦产量的组成性状之一。现有报道表明，多种植物激素参与了不同作物 GW 的调节。然而，茉莉酸（JA）的潜在作用尚不清楚。在这里，我们报告说，triticale 粒重 1（tgw1）突变体，其 GW 和 JA 含量均显著降低，是由于参与 JA 合成过程中β-氧化的酮酰硫解酶 2B（KAT-2B）的提前终止突变引起的。KAT-2B 的过表达增加了野生型的 GW，并提高了产量。此外，KAT-2B 可补充 tgw1 中的粒缺陷，并挽救拟南芥 kat2 突变体在无糖培养基中的致死表型。尽管 tgw1 突变体中 JA 合成受到抑制，但 ABA 合成上调，同时伴随着 SAG3 的表达增强和叶片中叶绿素含量的降低。总之，这些结果表明 JA 合成基因 KAT-2B 在控制 GW 中的作用及其在小麦改良中的潜在应用价值。
