Boutasknit Abderrahim, Baslam Marouane, Ait-El-Mokhtar Mohamed, Anli Mohamed, Ben-Laouane Raja, Douira Allal, El Modafar Cherkaoui, Mitsui Toshiaki, Wahbi Said, Meddich Abdelilah
Laboratory of Biotechnology and Plant Physiology, Faculty of Sciences Semlalia, Cadi Ayyad University, BP: 2390, Marrakesh 40000, Morocco.
Department of Applied Biological Chemistry, Faculty of Agriculture, Niigata University, Niigata 950-2181, Japan.
Plants (Basel). 2020 Jan 8;9(1):80. doi: 10.3390/plants9010080.
Irregular precipitation and drought caused an increase in tree mortality rates in multiple forest biomes with alterations in both ecosystem services and carbon balance. Carob () growth and production in arid and semi-arid ecosystems are likely affected by climate change-induced droughts. Understanding the physiological responses of drought-induced early-stage tree death and strategies to enhance drought tolerance and optimize growth will help tree improvement programs. Mycorrhizal inoculation has a pronounced impact on plant growth, water absorption, mineral nutrition, and protection from abiotic stresses. However, a better understanding of these complex interconnected cellular processes and arbuscular mycorrhizal fungi (AMF)-mediated mechanisms regulating drought tolerance in plants will enhance its potential application as an efficient approach for bio-amelioration of stresses. The objectives of this work were to elucidate the different effects of autochthone AMF on inorganic solute and water content uptakes, organic adjustments (sugar and proteins content), leaf gas exchange (stomatal conductance and efficiency of photosystems I and II), and oxidative damage of two contrasting ecotypes of carob seedlings: coastal (southern ecotype (SE)) and in-land (northern ecotype (NE)) under control (C), drought (by cessation of irrigation for 15 days (15D)), and recovery (R) conditions. Our findings showed that AMF promoted growth, nutrient content, and physiological and biochemical parameters in plants of both ecotypes during C, 15D, and R conditions. After four days of recovery, stomatal conductance (g), the maximum photochemical efficiency of PSII (F/F), water content, and plant uptake of mineral nutrients (P, K, Na, and Ca) were significantly higher in shoots of mycorrhizal (AM) than non-mycorrhizal (NM) control plants. Consequently, AMF reduced to a greater degree the accumulation of hydrogen peroxide (HO) and oxidative damage to lipid (malondialdehyde (MDA)) content in AM than NM plants in NE and SE, after recovery. Altogether, our findings suggest that AMF can play a role in drought resistance of carob trees at an early stage by increasing the inorganic solutes (P, K, Na, and Ca), water content uptake, organic solutes (soluble sugars and protein content), stomatal conductance, and defense response against oxidative damage during re-watering after drought stress.
降水不均和干旱导致多个森林生物群落的树木死亡率上升,生态系统服务和碳平衡也发生了改变。干旱和半干旱生态系统中角豆树()的生长和产量可能受到气候变化引发的干旱影响。了解干旱导致树木早期死亡的生理反应以及增强耐旱性和优化生长的策略,将有助于树木改良计划。菌根接种对植物生长、水分吸收、矿物质营养以及抵御非生物胁迫具有显著影响。然而,更好地理解这些复杂的相互关联的细胞过程以及丛枝菌根真菌(AMF)介导的调节植物耐旱性的机制,将增强其作为一种有效的生物改良胁迫方法的潜在应用价值。这项工作的目的是阐明本地AMF对两种对比生态型角豆幼苗(沿海(南方生态型(SE))和内陆(北方生态型(NE)))在对照(C)、干旱(通过停止灌溉15天(15D))和恢复(R)条件下无机溶质和水分吸收、有机调节(糖和蛋白质含量)、叶片气体交换(气孔导度以及光系统I和II的效率)以及氧化损伤的不同影响。我们的研究结果表明,在C、15D和R条件下,AMF促进了两种生态型植物的生长、养分含量以及生理和生化参数。恢复四天后,菌根(AM)植株地上部分的气孔导度(g)、PSII的最大光化学效率(F/F)、水分含量以及植物对矿物质营养(P、K、Na和Ca)的吸收显著高于非菌根(NM)对照植株。因此,恢复后,与NE和SE中的NM植株相比,AMF能更大程度地降低AM植株中过氧化氢(HO)的积累以及脂质氧化损伤(丙二醛(MDA)含量)。总之,我们的研究结果表明,AMF可以通过增加无机溶质(P、K、Na和Ca)、水分吸收、有机溶质(可溶性糖和蛋白质含量)、气孔导度以及干旱胁迫后复水期间对氧化损伤的防御反应,在角豆树早期抗旱中发挥作用。