Herbivorous Livestock Research Institute, Chongqing Academy of Animal Sciences, Chongqing, 402460, China.
College of Grassland Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China.
BMC Genomics. 2023 Aug 31;24(1):510. doi: 10.1186/s12864-023-09550-8.
Along with global warming, resulting in crop production, exacerbating the global food crisis. Therefore, it is urgent to study the mechanism of plant heat resistance. However, crop resistance genes were lost due to long-term artificial domestication. By analyzing the potential heat tolerance genes and molecular mechanisms in other wild materials, more genetic resources can be provided for improving the heat tolerance of crops. Elephant grass (Pennisetum purpureum Schum.) has strong adaptability to heat stress and contains abundant heat-resistant gene resources.
Through sequence structure analysis, a total of 36 RWP-RK members were identified in elephant grass. Functional analysis revealed their close association with heat stress. Four randomly selected RKDs (RKD1.1, RKD4.3, RKD6.6, and RKD8.1) were analyzed for expression, and the results showed upregulation under high temperature conditions, suggesting their active role in response to heat stress. The members of RWP-RK gene family (36 genes) in elephant grass were 2.4 times higher than that of related tropical crops, rice (15 genes) and sorghum (15 genes). The 36 RWPs of elephant grass contain 15 NLPs and 21 RKDs, and 73% of RWPs are related to WGD. Among them, combined with the DAP-seq results, it was found that RWP-RK gene family expansion could improve the heat adaptability of elephant grass by enhancing nitrogen use efficiency and peroxidase gene expression.
RWP-RK gene family expansion in elephant grass is closely related to thermal adaptation evolution and speciation. The RKD subgroup showed a higher responsiveness than the NLP subgroup when exposed to high temperature stress. The promoter region of the RKD subgroup contains a significant number of MeJA and ABA responsive elements, which may contribute to their positive response to heat stress. These results provided a scientific basis for analyzing the heat adaptation mechanism of elephant grass and improving the heat tolerance of other crops.
随着全球变暖，导致作物减产，加剧了全球粮食危机。因此，迫切需要研究植物耐热机制。然而，由于长期的人工驯化，作物的抗性基因已经丢失。通过分析其他野生材料中的潜在耐热基因和分子机制，可以为提高作物的耐热性提供更多的遗传资源。象草（Pennisetum purpureum Schum.）对热胁迫具有很强的适应性，并且含有丰富的耐热基因资源。
通过序列结构分析，在象草中共鉴定出 36 个 RWP-RK 成员。功能分析表明它们与热胁迫密切相关。随机选择的四个 RKDs（RKD1.1、RKD4.3、RKD6.6 和 RKD8.1）进行表达分析，结果表明在高温条件下上调，表明它们在应对热胁迫中发挥积极作用。象草 RWP-RK 基因家族（36 个基因）的成员是相关热带作物水稻（15 个基因）和高粱（15 个基因）的 2.4 倍。象草的 36 个 RWPs 包含 15 个 NLPs 和 21 个 RKDs，73%的 RWPs 与 WGD 有关。其中，结合 DAP-seq 结果，发现 RWP-RK 基因家族的扩张可以通过提高氮利用效率和过氧化物酶基因的表达来提高象草的耐热性。
象草 RWP-RK 基因家族的扩张与热适应进化和物种形成密切相关。与高温胁迫下的 NLP 亚组相比，RKD 亚组表现出更高的响应性。RKD 亚组启动子区域含有大量 MeJA 和 ABA 响应元件，这可能有助于它们对热胁迫的积极响应。这些结果为分析象草耐热机制和提高其他作物耐热性提供了科学依据。
