AgResearch Ltd., Palmerston North, New Zealand.
Department of Biochemistry, University of Otago, Dunedin, New Zealand.
PLoS One. 2022 Oct 13;17(10):e0275503. doi: 10.1371/journal.pone.0275503. eCollection 2022.
Under favourable conditions, perennial ryegrass (Lolium perenne) engineered to accumulated high lipid (HL) carbon sink in their leaves was previously shown to also enhance photosynthesis and growth. The greater aboveground biomass was found to be diminished in a dense canopy compared to spaced pots. Besides, the underlying genetic regulatory network linking between leaf lipid sinks and these physiological changes remains unknown. In this study, we demonstrated that the growth advantage was not displayed in HL Lolium grown in spaced pots under low lights. Under standard lights, analysis of differentiating transcripts in HL Lolium reveals that the plants had elevated transcripts involved in lipid metabolism, light capturing, photosynthesis, and sugar signalling while reduced expression of genes participating in sugar biosynthesis and transportation. The plants also had altered several transcripts involved in mitochondrial oxidative respiration and redox potential. Many of the above upregulated or downregulated transcript levels were found to be complemented by growing the plants under low light. Overall, this study emphasizes the importance of carbon and energy homeostatic regulatory mechanisms to overall productivity of the HL Lolium through photosynthesis, most of which are significantly impacted by low irradiances.
在有利条件下，先前已证明工程化的多年生黑麦草（Lolium perenne）在叶片中积累高脂质（HL）碳汇，还能增强光合作用和生长。与间隔盆栽相比，茂密冠层中发现地上生物量较大减少。此外，叶片脂质汇与这些生理变化之间的潜在遗传调控网络仍然未知。在这项研究中，我们表明，在低光照下生长在间隔盆栽中的 HL 黑麦草并未显示出生长优势。在标准光照下，对 HL 黑麦草分化转录本的分析表明，这些植物的脂质代谢、光捕获、光合作用和糖信号相关的转录本水平升高，而参与糖生物合成和运输的基因表达降低。植物还改变了几个参与线粒体氧化呼吸和氧化还原电势的转录本。许多上述上调或下调的转录本水平通过在低光照下生长植物得到补充。总的来说，这项研究强调了碳和能量稳态调节机制对 HL 黑麦草整体生产力的重要性，这些机制主要通过光合作用产生，而光合作用受光照强度的影响很大。
