Cavagnaro Timothy R, Sokolow Shannon K, Jackson Louise E
School of Biological Sciences, Monash University, Clayton, Vic. 3800, Australia.
Department of Land, Air and Water Resources, University of California Davis, One Shields Avenue, Davis, CA 95616-8627, USA.
Funct Plant Biol. 2007 Aug;34(8):730-736. doi: 10.1071/FP06340.
Arbuscular mycorrhizas are predicted to be important in defining plant responses to elevated atmospheric CO concentrations. A mycorrhiza-defective tomato (Solanum lycopersicum L.) mutant with reduced mycorrhizal colonisation (rmc) and its mycorrhizal wild-type progenitor (76R MYC+) were grown under ambient and elevated atmospheric CO concentrations (eCO) in a controlled environment chamber-based pot study. Plant growth, nutrient contents and mycorrhizal colonisation were measured four times over a 72-day period. The 76R MYC+ plants generally had higher concentrations of P, N and Zn than their rmc counterparts. Consistent with earlier studies, mycorrhizal colonisation was not affected by eCO. Growth of the two genotypes was very similar under ambient CO conditions. Under eCO the mycorrhizal plants initially had higher biomass, but after 72 days, biomass was lower than for rmc plants, suggesting that in this pot study the costs of maintaining carbon inputs to the fungal symbiont outweighed the benefits with time.
丛枝菌根被认为在确定植物对大气中二氧化碳浓度升高的反应中起着重要作用。在基于可控环境舱的盆栽试验中，将一种菌根定殖减少的菌根缺陷型番茄（Solanum lycopersicum L.）突变体（rmc）及其菌根野生型亲本（76R MYC+）置于环境大气二氧化碳浓度和升高的大气二氧化碳浓度（eCO）条件下培养。在72天的时间内对植物生长、养分含量和菌根定殖进行了四次测量。76R MYC+植株的磷、氮和锌浓度通常高于其rmc对应植株。与早期研究一致，菌根定殖不受eCO的影响。在环境二氧化碳条件下，两种基因型的生长非常相似。在eCO条件下，菌根植物最初具有较高的生物量，但72天后，生物量低于rmc植株，这表明在该盆栽试验中，随着时间的推移，维持向真菌共生体输入碳的成本超过了收益。
