Caddell Daniel, Langenfeld Noah J, Eckels Madigan Jh, Zhen Shuyang, Klaras Rachel, Mishra Laxmi, Bugbee Bruce, Coleman-Derr Devin
Plant Gene Expression Center, United States Department of Agriculture - Agricultural Research Service (USDA ARS), Albany, CA, United States.
Plant and Microbial Biology Department, University of California at Berkeley, Berkeley, CA, United States.
Front Plant Sci. 2023 Jan 19;14:1050483. doi: 10.3389/fpls.2023.1050483. eCollection 2023.
Plants compete for light partly by over-producing chlorophyll in leaves. The resulting high light absorption is an effective strategy for out competing neighbors in mixed communities, but it prevents light transmission to lower leaves and limits photosynthesis in dense agricultural canopies. We used a CRISPR/Cas9-mediated approach to engineer rice plants with truncated light-harvesting antenna (TLA) via knockout mutations to individual antenna assembly component genes CpSRP43, CpSRP54a, and its paralog, CpSRP54b. We compared the photosynthetic contributions of these components in rice by studying the growth rates of whole plants, quantum yield of photosynthesis, chlorophyll density and distribution, and phenotypic abnormalities. Additionally, we investigated a Poales-specific duplication of CpSRP54. The Poales are an important family that includes staple crops such as rice, wheat, corn, millet, and sorghum. Mutations in any of these three genes involved in antenna assembly decreased chlorophyll content and light absorption and increased photosynthesis per photon absorbed (quantum yield). These results have significant implications for the improvement of high leaf-area-index crop monocultures.
植物部分通过在叶片中过度产生叶绿素来竞争光照。由此产生的高吸光率是在混合群落中胜过邻居的有效策略，但它会阻止光线透射到下部叶片，并限制密集农业冠层中的光合作用。我们使用CRISPR/Cas9介导的方法，通过对单个天线组装组件基因CpSRP43、CpSRP54a及其旁系同源基因CpSRP54b进行敲除突变，来培育具有截短光捕获天线（TLA）的水稻植株。我们通过研究整株植物的生长速率、光合作用的量子产率、叶绿素密度和分布以及表型异常，比较了这些组件在水稻中的光合贡献。此外，我们研究了CpSRP54在禾本目植物中的特异性复制。禾本目是一个重要的科，包括水稻、小麦、玉米、小米和高粱等主要作物。参与天线组装的这三个基因中的任何一个发生突变，都会降低叶绿素含量和光吸收，并增加每吸收一个光子的光合作用（量子产率）。这些结果对高叶面积指数作物单作的改良具有重要意义。
