Targeting plant cysteine oxidase activity for improved submergence tolerance.
Targeting plant cysteine oxidase activity for improved submergence tolerance.
复制标题
针对植物半胱氨酸氧化酶活性以提高耐淹性。
DOI：
10.1111/tpj.15605
复制
发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Taylor-Kearney LJ
中科院分区：
文献类型：
--
作者：
Taylor-Kearney LJ
植物半胱氨酸氧化酶(PCOS)是一种植物O2感受酶。它们催化O2依赖的步骤，通过N-degron途径启动VII族乙烯反应转录因子(ERF-VIIs)的蛋白酶体降解。当被淹没时，植物的氧气利用率降低；PCO活性因此降低，随之而来的ERF-VII稳定导致低氧反应基因上调，使其能够适应低氧气条件。由此产生的适应包括进入厌氧静止状态以维持能量储备，以及快速生长以躲避洪水并允许氧气运输到水下组织。ERF-VIIs的稳定与拟南芥、水稻和大麦在淹水后存活率的提高有关。由于气候变化和越来越多的洪灾事件，人们有兴趣操纵PCO/ERF-VII相互作用，将其作为提高不耐洪灾作物产量的一种方法。实现这一目标的有效方法可能是通过抑制PCO；然而，完全去除PCO活性对生长和表型不利，可能是由于其他PCO介导的作用。因此，靶向PCOS将需要暂时的化学抑制或精心设计酶结构来操纵其O2敏感性和/或底物特异性。充分的PCO结构和功能信息应该使这成为可能，因为在 中设计定点突变的潜力活着的CRISPR介导的碱基编辑。在这里，我们讨论合理操纵PCOS以实现ERF-VII稳定而不会造成产量损失所需的知识。我们还从生物催化领域获得灵感，考虑如何加快酶工程作为提高植物抗逆性和生产力的更广泛战略。
Plant cysteine oxidases (PCOs) are plant O2‐sensing enzymes. They catalyse the O2‐dependent step which initiates the proteasomal degradation of Group VII ethylene response transcription factors (ERF‐VIIs) via the N‐degron pathway. When submerged, plants experience a reduction in O2availability; PCO activity therefore decreases and the consequent ERF‐VII stabilisation leads to upregulation of hypoxia‐responsive genes which enable adaptation to low O2conditions. Resulting adaptations include entering an anaerobic quiescent state to maintain energy reserves and rapid growth to escape floodwater and allow O2transport to submerged tissues. Stabilisation of ERF‐VIIs has been linked to improved survival post‐submergence in Arabidopsis, rice (Oryza sativa) and barley (Hordeum vulgare). Due to climate change and increasing flooding events, there is an interest in manipulating the PCO/ERF‐VII interaction as a method of improving yields in flood‐intolerant crops. An effective way of achieving this may be through PCO inhibition; however, complete ablation of PCO activity is detrimental to growth and phenotype, likely due to other PCO‐mediated roles. Targeting PCOs will therefore require either temporary chemical inhibition or careful engineering of the enzyme structure to manipulate their O2sensitivity and/or substrate specificity. Sufficient PCO structural and functional information should make this possible, given the potential to engineer site‐directed mutagenesisin vivousing CRISPR‐mediated base editing. Here, we discuss the knowledge still required for rational manipulation of PCOs to achieve ERF‐VII stabilisation without a yield penalty. We also take inspiration from the biocatalysis field to consider how enzyme engineering could be accelerated as a wider strategy to improve plant stress tolerance and productivity.