不同菌根类型植物生物量分配对干旱的响应

Drought-induced biomass allocation responses in different types of mycorrhizal plants

基于干旱对全球植物生物量分配影响的数据库,选择丛枝菌根(AM)、外生菌根(ECM)和二者兼生型菌根(AM+ECM)3种最常见的菌根类型,研究3种菌根类型植物应对干旱时各器官生物量分配的变化,采用一般线性模型模拟分析器官间的相对生长速率,探索不同菌根类型植物生物量分配对干旱的响应。结果表明:在干旱条件下,AM和AM+ECM植物根系生物量(M_(R))的分配率分别增加了8.2%和7.6%,而ECM植物对M_(R)的分配则无显著变化;干旱导致AM植物茎生物量(M_(S))分配率降低了7.7%,ECM和AM+ECM植物对M_(S)的分配则无显著变化;干旱使得AM+ECM植物和ECM植物叶生物量(M_(L))的分配率分别下降了9.4%和6.5%,AM植物M_(L)则无显著变化;不同菌根类型植物遭受干旱时,AM和AM+ECM植物根、茎、叶的生物量积累速率依次降低,ECM植物茎、叶、根的生物量积累速率依次降低;不同菌根类型植物对干旱响应的策略不同,AM植物通过降低茎和生殖器官的生物量分配来提高对根的生物量分配;AM+ECM植物则更倾向于通过降低叶片生物量的分配来增加对根系的分配;ECM植物则仅仅是降低了叶片的生物量,根和茎生物量无显著变化。在考虑植物对干旱响应策略时,菌根应是重要的考虑因素。

Utilizing a global database detailing the impact of drought on plant biomass allocation,this study focused on the three most prevalent types:arbuscular mycorrhiza(AM),ectomycorrhiza(ECM)and amphigenetic mycorrhiza(AM+ECM).The goal was to explore alterations in organ-specific biomass allocation in thesemycorrhizal plants in response to drought.Employing a general linear model,the relative growth rate among organs was simulated and analyzed,shedding light on how different mycorrhizal plants adjust their biomass allocation in reaction to drought.The results revealed that under drought conditions,the allocation of root biomass(MR)increased by 8.2%for AM plants and 7.6%for AM+ECM plants,while ECM plants exhibited no significant change in the allocation of MR.The allocation of stem biomass(MS)decreased by 7.7%for AM plants under drought condition,but remained constant for ECM and AM+ECM plants.The allocation of leaf biomass(ML)experienced a decrease of 9.4%for AM+ECMplants and 6.5%for ECM plants under drought,while MLof AM plants remained relatively stable.When subjected to drought,the biomass accumulation rates of roots,stems and leaves followed a decreasing pattern for AM and AM+ECM plants.Conversely,ECM plants witnessed a decreasing accumulation pattern for stems,leaves and roots.The strategies employed by different mycorrhizal plants in response to drought diverge:AM plants increased roots biomass by decreasing the biomass allocation of stems and reproductive organs,AM+ECM plants prioritized augmenting root biomass through diminished leaf biomass allocation,and ECM plants solelydecreased the biomass of leaveswith minimal changes in the biomass of roots and stems.Consequently,mycorrhiza emerges as apivotal factor when contemplating plant response strategies to drought.