Bárzana Gloria, Aroca Ricardo, Ruiz-Lozano Juan Manuel
Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín (CSIC), Granada, 18008, Spain.
Plant Cell Environ. 2015 Aug;38(8):1613-27. doi: 10.1111/pce.12507. Epub 2015 Mar 4.
The arbuscular mycorrhizal (AM) symbiosis alters host plant physiology under drought stress, but no information is available on whether or not the AM affects respond to drought locally or systemically. A split-root system was used to obtain AM plants with total or only half root system colonized as well as to induce physiological drought affecting the whole plant or non-physiological drought affecting only the half root system. We analysed the local and/or systemic nature of the AM effects on accumulation of osmoregulatory compounds and aquaporins and on antioxidant systems. Maize plants accumulated proline both, locally in roots affected by drought and systemically when the drought affected the whole root system, being the last effect ampler in AM plants. PIPs (plasma membrane intrinsic proteins) aquaporins were also differently regulated by drought in AM and non-AM root compartments. When the drought affected only the AM root compartment, the rise of lipid peroxidation was restricted to such compartment. On the contrary, when the drought affected the non-AM root fraction, the rise of lipid peroxidation was similar in both root compartments. Thus, the benefits of the AM symbiosis not only rely in a lower oxidative stress in the host plant, but it also restricts locally such oxidative stress.
丛枝菌根（AM）共生关系在干旱胁迫下会改变宿主植物的生理状况，但关于AM是局部还是系统地响应干旱，尚无相关信息。采用分根系统来培育菌根定殖于全部或仅一半根系的植株，同时诱导影响全株的生理性干旱或仅影响一半根系的非生理性干旱。我们分析了AM对渗透调节化合物和水通道蛋白积累以及抗氧化系统影响的局部和/或系统性质。玉米植株在受干旱影响的根系局部积累脯氨酸，当干旱影响整个根系时则在全株系统积累，后一种效应在菌根植株中更为显著。质膜内在蛋白（PIPs）水通道蛋白在菌根和非菌根根区室中受干旱的调控也有所不同。当干旱仅影响菌根根区室时，脂质过氧化作用的增强仅限于该区域。相反，当干旱影响非菌根根系部分时，两个根区室中脂质过氧化作用的增强情况相似。因此，AM共生关系的益处不仅在于降低宿主植物的氧化应激，还在于局部限制这种氧化应激。
