Graduate Program of Plant Biotechnology, Federal University of Lavras, Lavras 37203-202, MG, Brazil.
The Brazilian Agricultural Research Corporation, Embrapa Agroenergy, Brasília 70770-901, DF, Brazil.
Int J Mol Sci. 2023 Aug 18;24(16):12918. doi: 10.3390/ijms241612918.
An oil palm ( Jacq.) bud rod disorder of unknown etiology, named Fatal Yellowing (FY) disease, is regarded as one of the top constraints with respect to the growth of the palm oil industry in Brazil. FY etiology has been a challenge embraced by several research groups in plant pathology throughout the last 50 years in Brazil, with no success in completing Koch's postulates. Most recently, the hypothesis of having an abiotic stressor as the initial cause of FY has gained ground, and oxygen deficiency (hypoxia) damaging the root system has become a candidate for stress. Here, a comprehensive, large-scale, single- and multi-omics integration analysis of the metabolome and transcriptome profiles on the leaves of oil palm plants contrasting in terms of FY symptomatology-asymptomatic and symptomatic-and collected in two distinct seasons-dry and rainy-is reported. The changes observed in the physicochemical attributes of the soil and the chemical attributes and metabolome profiles of the leaves did not allow the discrimination of plants which were asymptomatic or symptomatic for this disease, not even in the rainy season, when the soil became waterlogged. However, the multi-omics integration analysis of enzymes and metabolites differentially expressed in asymptomatic and/or symptomatic plants in the rainy season compared to the dry season allowed the identification of the metabolic pathways most affected by the changes in the environment, opening an opportunity for additional characterization of the role of hypoxia in FY symptom intensification. Finally, the initial analysis of a set of 56 proteins/genes differentially expressed in symptomatic plants compared to the asymptomatic ones, independent of the season, has presented pieces of evidence suggesting that breaks in the non-host resistance to non-adapted pathogens and the basal immunity to adapted pathogens, caused by the anaerobic conditions experienced by the plants, might be linked to the onset of this disease. This set of genes might offer the opportunity to develop biomarkers for selecting oil palm plants resistant to this disease and to help pave the way to employing strategies to keep the safety barriers raised and strong.
一种病因不明的油棕芽枯病，被称为致命黄化（FY）病，被认为是巴西棕榈油产业发展的主要制约因素之一。FY 的病因是过去 50 年来巴西植物病理学研究小组面临的挑战之一，尽管他们进行了多项研究，但仍未能完成科赫假设。最近，有一种假设认为，非生物胁迫因素是 FY 的最初原因，而根系缺氧（缺氧）是造成胁迫的候选因素。在这里，我们报告了对 FY 症状表现为有症状和无症状的油棕叶片进行代谢组学和转录组学的综合、大规模、单一和多组学整合分析，这些叶片样本是在两个不同季节（旱季和雨季）收集的。尽管观察到土壤的物理化学特性以及叶片的化学特性和代谢组图谱发生了变化，但仍无法区分无症状或有症状的油棕植株，即使在雨季土壤积水时也无法区分。然而，与旱季相比，雨季时无症状和/或有症状植株中差异表达的酶和代谢物的多组学整合分析，能够鉴定出受环境变化影响最大的代谢途径，为进一步研究缺氧在 FY 症状加剧中的作用提供了机会。最后，对一组在雨季与旱季相比差异表达的 56 种蛋白质/基因进行的初步分析表明，与非适应病原体的非寄主抗性和适应病原体的基础免疫有关的断裂，可能与该病的发生有关。这些基因可能为选择对 FY 病具有抗性的油棕植株提供了机会，并有助于为采用保持安全屏障的策略铺平道路。
