College of Chemistry and Life Sciences , Zhejiang Normal University , Jinhua , Zhejiang 321004 , People's Republic of China.
State Key Laboratory of Rice Biology , China National Rice Research Institute , Hangzhou , Zhejiang 310006 , People's Republic of China.
J Agric Food Chem. 2019 Jul 3;67(26):7249-7257. doi: 10.1021/acs.jafc.9b01676. Epub 2019 Jun 21.
The duration of the rice growth phase has always been an important target trait. The identification of mutations in rice that alter these processes and result in a shorter growth phase could have potential benefits for crop production. In this study, we isolated an early aging rice mutant, pe-1, with light green leaves, using γ-mutated indica rice cultivar and subsequent screening methods, which is known as the phytochrome synthesis factor Se5 that controls rice flowering. The pe-1 plant is accompanied by a decreased chlorophyll content, an enhanced photosynthesis, and a decreased pollen fertility. PE-1, a close homologue of HY1, is localized in the chloroplast. Expression pattern analysis indicated that PE-1 was mainly expressed in roots, stems, leaves, leaf sheaths, and young panicles. The knockout of PE-1 using the CRISPR/Cas9 system decreased the chlorophyll content and downregulated the expression of PE-1-related genes. Furthermore, the chloroplasts of pe-1 were filled with many large-sized starch grains, and the number of osmiophilic granules (a chloroplast lipid reservoir) was significantly decreased. Altogether, our findings suggest that PE-1 functions as a master regulator to mediate in chlorophyll biosynthesis and photosynthetic pathways.
水稻生长阶段的持续时间一直是一个重要的目标特征。鉴定改变这些过程并导致生长阶段缩短的水稻突变，可能对作物生产有潜在的好处。在这项研究中，我们使用γ诱变籼稻品种和后续的筛选方法，分离出一个早期衰老的水稻突变体 pe-1，其叶片呈淡绿色，该突变体被称为控制水稻开花的光合成色素合成因子 Se5。pe-1 植株伴随着叶绿素含量降低、光合作用增强和花粉育性降低。PE-1 是 HY1 的紧密同源物，定位于叶绿体中。表达模式分析表明，PE-1 主要在根、茎、叶、叶鞘和幼穗中表达。使用 CRISPR/Cas9 系统敲除 PE-1 降低了叶绿素含量，并下调了与 PE-1 相关基因的表达。此外，pe-1 的叶绿体中充满了许多大尺寸的淀粉粒，并且嗜锇颗粒（叶绿体脂质库）的数量显著减少。总之，我们的研究结果表明，PE-1 作为一个主调控因子，调节叶绿素生物合成和光合作用途径。
