砂漠植物とゾウムシの相互作用における過剰補償を発見(Study Reveals Overcompensation in Desert Plant-Weevil Interactions)

2026-11-09 中国科学院(CAS)

中国科学院新疆生態地理研究所の研究チームは、中国北西部のグルバントンギュト砂漠に生育する一年生植物 Strigosella scorpioides と、その茎に産卵するゾウムシ Lixus ochraceus の相互作用を調査し、昆虫の食害を受けた植物の成長・繁殖が、かえって促進される「過剰補償(Overcompensation)」現象を明らかにした。自然状態の被害株と非被害株を比較した結果、被害株は成長最盛期の総バイオマスが約2.2倍、果実数が約2.1倍に達した。被害株では植物の防御物質であるグルコシノレート類が減少し、揮発性成分のベンジルイソチオシアネートとベンズアルデヒドの組成も変化していた。ベンズアルデヒドは高濃度で雌のゾウムシを忌避させる作用を示した。また、被害株由来の種子は、特定の春季温度条件下で発芽率が高かった。これらの結果は、食害の程度、植物の成長段階、化学的防御機構などが植物と昆虫の相互作用を左右することを示している。砂漠生態系における植物の耐食害戦略と生物間相互作用の理解を深める成果である。

砂漠植物とゾウムシの相互作用における過剰補償を発見(Study Reveals Overcompensation in Desert Plant-Weevil Interactions)

Phenological synchrony between Strigosella scorpioides and the stem-boring weevil Lixus ochraceus, and the development of the weevil inside the host plant. (Image by XIEG)

<関連情報>

茎穿孔性ゾウムシLixus ochraceusと砂漠に一時的に生息するStrigosella scorpioidesの間に潜在的に促進的な相互作用が存在することを示す証拠 Evidence for a Potentially Facilitative Interaction Between the Stem-Boring Weevil Lixus ochraceus and the Desert Ephemeral Strigosella scorpioides

Lan Zhang, Huiliang Liu, Xiaohu Wen, Lingwei Zhang, Yanfeng Chen, Carol C. Baskin, Jerry M. Baskin, Yuanming Zhang

Plant, Cell & Environment  Published: 07 October 2026

DOI:https://doi.org/10.1111/pce.70909

Abstract

Plant–herbivore interactions are typically antagonistic, but abiotic stress and compressed life cycles can alter both their intensity and net outcome. Herbivory is generally expected to reduce plant fitness, yet how desert ephemerals respond to low-intensity stem boring remains poorly resolved. We characterised the natural association between the desert ephemeral Strigosella scorpioides and its specialist stem-boring weevil Lixus ochraceus in the Gurbantunggut Desert, northwestern China, combining phenotypic monitoring, tissue nutrient and secondary-metabolite analyses, volatile profiling, behavioural assays and germination trials. Infestation intensity was uniformly low, with each host plant harbouring a single larva. Relative to non-host neighbours, host plants were taller, produced more branches and developed greater leaf area, and attained 2.2-fold greater peak biomass and 2.1-fold greater fruit production, consistent with overcompensation. Host plants contained lower concentrations of three glucosinolates and emitted distinct volatile blends, with a lower proportion of benzyl isothiocyanate and a higher proportion of benzaldehyde; in behavioural assays, females responded to both compounds in a concentration-dependent manner. Seeds from host plants germinated at higher rates under simulated spring snowmelt temperature regimes, although this advantage was temperature-dependent. Together, these results suggest that low-intensity stem boring can coincide with enhanced plant performance and fitness in a highly compressed growing season, and point to plant chemical traits as candidate mediators of plant–herbivore interactions in arid ecosystems. These findings challenge the prevailing assumption that herbivory is invariably antagonistic, suggesting that the sign of such interactions may be more labile than commonly recognised where brief resource windows and close phenological synchrony align.

1207植物保護
ad
ad
Follow
ad
タイトルとURLをコピーしました