Ketumile Dikungwa, Yang Xiaodong, Sanchez Robersy, Kundariya Hardik, Rajewski John, Dweikat Ismail M, Mackenzie Sally A
Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE, United States.
Department of Biology, The Pennsylvania State University, University Park, PA, United States.
Front Plant Sci. 2022 Jan 27;12:798243. doi: 10.3389/fpls.2021.798243. eCollection 2021.
Crop resilience and yield stability are complex traits essential for food security. is an important grain crop that shows promise for its natural resilience to drought and potential for marginal land production. We have developed sorghum lines in the Tx430 genetic background suppressed for expression as a means of inducing epigenetic variation, and have used these materials to evaluate changes in plant growth vigor. Plant crossing and selection in two distinct environments revealed features of phenotypic plasticity derived from manipulation. Introduction of an epigenetic variation to an isogenic sorghum population, in the absence of selection, resulted in 10% yield increase under ideal field conditions and 20% increase under extreme low nitrogen conditions. However, incorporation of early-stage selection amplified these outcomes to 36% yield increase under ideal conditions and 64% increase under marginal field conditions. Interestingly, the best outcomes were derived by selecting mid-range performance early-generation lines rather than highest performing. Data also suggested that phenotypic plasticity derived from the epigenetic variation was non-uniform in its response to environmental variability but served to reduce genotype × environment interaction. The MSH1-derived growth vigor appeared to be associated with enhanced seedling root growth and altered expression of auxin response pathways, and plants showed evidence of cold tolerance, features consistent with observations made previously in Arabidopsis. These data imply that the MSH1 system is conserved across plant species, pointing to the value of parallel model plant studies to help devise effective plant selection strategies for epigenetic breeding in multiple crops.
作物抗逆性和产量稳定性是保障粮食安全的复杂性状。高粱是一种重要的谷类作物，因其对干旱的天然抗性和在边际土地上的生产潜力而备受关注。我们在Tx430遗传背景下培育了抑制MSH1表达的高粱品系，以此诱导表观遗传变异，并利用这些材料评估植物生长活力的变化。在两种不同环境下进行植物杂交和选择，揭示了由MSH1操纵产生的表型可塑性特征。在没有选择的情况下，向同基因高粱群体引入表观遗传变异后，在理想田间条件下产量提高了10%，在极端低氮条件下提高了20%。然而，纳入早期选择后，这些结果在理想条件下产量提高到36%，在边际田间条件下提高到64%。有趣的是，最佳结果来自选择中期表现的早期世代品系，而不是表现最佳的品系。数据还表明，由表观遗传变异产生的表型可塑性对环境变异性的反应并不均匀，但有助于减少基因型×环境互作。源自MSH1的生长活力似乎与幼苗根系生长增强和生长素反应途径的表达改变有关，并且植株表现出耐寒性，这些特征与之前在拟南芥中的观察结果一致。这些数据表明MSH1系统在不同植物物种中是保守的，这表明平行模式植物研究有助于为多种作物的表观遗传育种设计有效的植物选择策略。
