Plagiodera versicolora feeding induces systemic and sexually differential defense responses in poplars

Abstract

Dioecious plants have evolved effective defense strategies to deal with various biotic and abiotic stresses. However, little is known regarding sexual differences in their defense against herbivores. In this study, we investigated the mechanism of systemic defense responses in male and female Populus cathayana attacked by Plagiodera versicolora Laicharting. The results revealed that P. cathayana exhibits sexually differential responses to a defoliator. The percentage of damaged leaf area was greater in males than in females. Furthermore, the observed saccharide changes imply that males and females exhibit different response times to defoliators. The contents of flavonoids and anthocyanins were significantly increased in both sexes but were higher in females. Specifically, the jasmonic acid (JA) pathway plays an important role. Expression of pest‐related genes further revealed that hormones induce changes in downstream genes and metabolites, and upregulation of JA ZIM‐domain (JAZ) and CORONATINE INSENSITIVE 1 (COI1) was more significant in females. In the undamaged adjacent leaves, metabolite and gene changes displayed similar patterns to the damaged local leaves, but levels of JA, JAZ1, and COI1 were higher in females. Therefore, our data confirmed that plants initiate the JA pathway to defend against herbivores, that there is systematic signal transduction, and that this ability is stronger in females than in males. This study provides new insights into the resistance of dioecious plants to herbivory and adds a new theoretical basis for the systemic signal transduction of plants in response to biotic stress.

Novel Jasmonic Acid–Coumarin Pathway in the Eggplant That Inhibits Vitellogenin Gene Expression To Prevent Mite Reproduction

“…10,29 Upon a wounding signal or invasion by insects and pathogens, the JA content increases, initiating the plant defense response. 30 The present study also discovered that mite infestation increased the JA content in eggplants. In most plants, the molecular mechanism responsible for the increased JA content is often associated with the upregulation of pathway genes.…”

“…JA, a crucial endogenous growth regulator in plants, plays a vital role in plant development and defense. , Upon a wounding signal or invasion by insects and pathogens, the JA content increases, initiating the plant defense response . The present study also discovered that mite infestation increased the JA content in eggplants.…”

Transcriptomic Analysis Revealed That Low-Density Aphid Infestation Temporarily Changes Photosynthesis and Disease Resistance but Persistently Promotes Insect Resistance in Poplar Leaves

“…In addition, research has also illustrated that insect herbivory increases the accumulation of flavonoids, a chemical defense substance for insects in different plants [40][41][42]. The contents of flavonoids and anthocyanins were significantly increased in both sexes but were higher in females [43]. Therefore, in this study, this defensive behavior was described as plant resistance but not plant tolerance, with regard to aphids.…”

Plant volatiles and priority effects interactively determined initial community assembly of arthropods on multiple willow species

“…Induced defense also depends on the types of herbivory (chewer vs. sucker), and is related to priority effects (Stam et al, 2018 ). P. versicolora , common herbivore in Salicaceae species, initiates the jasmonic acid pathway (Liu et al, 2022 ) and would negatively affect the late emerging conspecifics' performance (Yoneya et al, 2014 ) and its population dynamics (Yoneya et al, 2023 ). Additionally, at the interannual scale, willow species in floodplain often show compensatory regrowth after herbivory and physical damages, leading to greater resource availability and better nutritious quality (e.g., lower C:N ratio) for herbivores (Nakamura et al, 2005 , 2006 ).…”