Rodrigues Ana M, Carrasquinho Isabel, António Carla
Plant Metabolomics Laboratory, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
Instituto Nacional Investigação Agrária e Veterinária I.P., Oeiras, Portugal.
Front Plant Sci. 2021 Nov 24;12:777681. doi: 10.3389/fpls.2021.777681. eCollection 2021.
The pinewood nematode (PWN) is the causal agent of the pine wilt disease (PWD) and represents one of the major threats to conifer forests. The detection of the PWN in Portugal, associated with , increased the concern of its spread to European forests. Despite its susceptibility to PWD, genetic variability found among populations has been associated with heritable PWD resistance. Understanding the mechanisms underlying tree resistance constitutes a valuable resource for breeding programs toward more resilient forest plantations. This study investigated changes in anatomy, chlorophyll fluorescence (ChlF), and primary metabolism in susceptible and resistant half-sib plants, after PWN inoculation. Susceptible plants showed a general shutdown of central metabolism, osmolyte accumulation, photosynthetic inhibition, and a decrease in the plant water status. The ChlF transient rise (OJIP curve) revealed the appearance of L- and K-bands, indicators of environmental stress. In contrast, resistant plants revealed a regulated defense response and were able to restrict PWN migration and cellular damage. Furthermore, the accumulation of γ-aminobutyric acid (GABA) and succinate suggested a role of these metabolites in PWD resistance and the possible activation of the GABA shunt. Altogether, these results provide new insights to the role of primary metabolism in PWD resistance and in the selection of resistant phenotypes for disease mitigation.
松材线虫（PWN）是松材线虫病（PWD）的致病因子，是针叶林面临的主要威胁之一。在葡萄牙检测到与[相关内容缺失]有关的松材线虫，增加了人们对其向欧洲森林扩散的担忧。尽管其对松材线虫病敏感，但在[种群相关内容缺失]种群中发现的遗传变异性与可遗传的松材线虫病抗性有关。了解树木抗性的潜在机制是培育更具抗逆性人工林育种计划的宝贵资源。本研究调查了易感和抗性半同胞植株在接种松材线虫后，其解剖结构、叶绿素荧光（ChlF）和初级代谢的变化。易感植株表现出中心代谢普遍停止、渗透溶质积累、光合作用抑制以及植物水分状况下降。叶绿素荧光瞬态上升（OJIP曲线）显示出现了L波段和K波段，这是环境胁迫的指标。相比之下，抗性植株表现出有调控的防御反应，能够限制松材线虫的迁移和细胞损伤。此外，γ-氨基丁酸（GABA）和琥珀酸的积累表明这些代谢物在松材线虫病抗性中发挥作用，以及可能激活了GABA分流途径。总之，这些结果为初级代谢在松材线虫病抗性中的作用以及为减轻病害选择抗性表型提供了新的见解。
