地上與地下生物的相互聯(lián)系是當(dāng)代生態(tài)學(xué)研究的熱點(diǎn)。而大氣CO2濃度升高是未來發(fā)生的一種趨勢。由于茉莉酸誘導(dǎo)抗性途徑產(chǎn)生的系統(tǒng)防御信號(hào)能夠貫串植物的地上,、地下部分,，因此研究植物的茉莉酸誘導(dǎo)抗性途徑可以將大氣CO2濃度升高和地下線蟲為害有機(jī)的聯(lián)系起來,，探討大氣CO2濃度升高如何通過植物產(chǎn)生級(jí)聯(lián)效應(yīng)（cascading effect）影響地下生物,。
中科院動(dòng)物研究所種群生態(tài)與全球變化研究組科研人員在野外的開頂式CO2控制箱（OTC）中，利用茉莉酸防御途徑加強(qiáng)型番茄35S,、茉莉酸防御途徑缺失型番茄spr2和野生型番茄Wt三種試驗(yàn)植物,，研究了大氣CO2濃度倍增（750ppm）環(huán)境下，三種基因型番茄對南方根結(jié)線蟲抗性的變化,。
研究發(fā)現(xiàn),，高CO2濃度增加了三種基因型番茄的碳含量和碳氮比，加快了植物的生長發(fā)育,；同時(shí),，大氣CO2濃度升高降低了茉莉酸防御途徑加強(qiáng)型番茄35S對線蟲的抗性，而對于野生型番茄Wt和茉莉酸防御途徑缺失型番茄spr2沒有影響,，表明茉莉酸信號(hào)途徑參與并加強(qiáng)了植物對線蟲的防御,；而對照CO2濃度環(huán)境中，茉莉酸防御途徑缺失型番茄spr2與野生型番茄Wt相比,，對線蟲的抗性差異并不明顯,，說明在植物對線蟲的防御過程中，茉莉酸信號(hào)途徑并不是唯一的抗性途徑,。
研究結(jié)果提示：不同基因型的番茄,，即使僅有一個(gè)基因的差異，對大氣CO2濃度升高的響應(yīng)也存在差異,，這種差異是植株?duì)I養(yǎng)和防御物質(zhì)的權(quán)衡表現(xiàn),，進(jìn)而導(dǎo)致不同基因型番茄在未來環(huán)境下對線蟲抗性的變化。
該文第一作者孫玉誠為種群生態(tài)與全球變化研究組助理研究員,，通訊作者為戈峰研究員,。該研究工作得到了國家重大基礎(chǔ)研究計(jì)劃（973）、中國科學(xué)院知識(shí)創(chuàng)新工程重要方向項(xiàng)目和基金委創(chuàng)新研究群體項(xiàng)目的資助。(生物谷Bioon.com)
生物谷推薦原文出處：
Plant, Cell & Environment DOI:10.1111/j.1365-3040.2009.02098.x
Elevated CO2 changes the interactions between nematode and tomato genotypes differing in the JA pathway
YUCHENG SUN, HAIFENG CAO, JIN YIN, LE KANG & FENG GE
Interactions between the root-knot nematode Meloidogyne incognita and three isogenic tomato (Lycopersicon esculentum) genotypes were examined when plants were grown under ambient (370 ppm) and elevated (750 ppm) CO2. We tested the hypothesis that, defence-recessive genotypes tend to allocate 'extra' carbon (relative to nitrogen) to growth under elevated CO2, whereas defence-dominated genotypes allocate extra carbon to defence, and thereby increases the defence against nematodes. For all three genotypes, elevated CO2 increased height, biomass, and root and leaf total non-structural carbohydrates (TNC):N ratio, and decreased amino acids and proteins in leaves. The activity of anti-oxidant enzymes (superoxide dismutase and catalase) was enhanced by nematode infection in defence-recessive genotypes. Furthermore, elevated CO2 and nematode infection did not qualitatively change the volatile organic compounds (VOC) emitted from plants. Elevated CO2 increased the VOC emission rate only for defence-dominated genotypes that were not infected with nematodes. Elevated CO2 increased the number of nematode-induced galls on defence-dominated genotypes but not on wild-types or defence-recessive genotypes roots. Our results suggest that CO2 enrichment may not only increase plant C : N ratio but can disrupt the allocation of plant resources between growth and defence in some genetically modified plants and thereby reduce their resistance to nematodes.
