How drought and salinity affect arbuscular mycorrhizal symbiosis and strigolactone biosynthesis?

• Published in: Planta 2016-06, Vol.243 (6), p.1375-1385
• Main Author: López-Ráez, Juan A.
• Format: Article
• Language: English
• Subjects: Agriculture; Biomedical and Life Sciences; Biosynthesis; Biosynthetic Pathways; Crop production; Cyclopentanes - metabolism; Drought; Droughts; Ecology; Environmental changes; Environmental conditions; Forestry; Hormones; Intensive farming; Lactones - chemistry; Lactones - metabolism; Life Sciences; Microorganisms; Mycorrhizae - metabolism; Mycorrhizae - physiology; Natural resources; Oxylipins - metabolism; Plant Growth Regulators - biosynthesis; Plant Growth Regulators - chemistry; Plant Growth Regulators - physiology; Plant Sciences; Plasticity; REVIEW; Salinity; Salt-Tolerance; Sodium Chloride - metabolism; Soil microorganisms; Stress, Physiological; Strigolactones; Symbiosis; Water - metabolism; Water availability
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s00425-015-2435-9

Plants are very dynamic systems with a great capacity for adaptation to a constantly changing environment. This phenotypic plasticity is particularly advantageous in areas damaged or subjected to intensive agriculture. Nowadays, global crop production systems are intensifying the impact on natural resources, such as water availability. Therefore, there is an urgent need to find more sustainable alternatives. One of the plant strategies to improve phenotypic plasticity is to establish mutualistic beneficial associations with soil microorganisms, such as the arbuscular mycorrhizal (AM) fungi. The establishment of AM symbiosis requires a complex network of interconnected signalling pathways, in which phytohormones play a key role. Strigolactones (SLs) are plant hormones acting as modulators of the coordinated development under nutrient shortage. SLs also act as host detection signals for AM fungi, favouring symbiosis establishment. In this review, current knowledge on the effect of water-related stresses, such as drought and salinity, in AM symbiosis and in SL production is discussed. Likewise, how the symbiosis helps the host plant to alleviate stress symptoms is also reviewed. Finally, we highlight how interactions between hormonal signalling pathways modulate all these responses, especially in the cross-talk between SLs and abscisic acid (ABA). Understanding the intricate mechanisms that regulate the establishment of AM symbiosis and the plant responses under unfavourable conditions will contribute to implement the use of AM fungi as bioprotective agents against these stresses.