Arbuscular mycorrhiza improved growth performance in Macadamia tetraphylla L. grown under water deficit stress involves soluble sugar and proline accumulation

Abstract

Water deficit limits plant growth and yield. Arbuscular mycorrhizal (AM) symbiosis is viewed as one of the several methods to improve growth under water deficit. The present study investigated the growth performance in relation to water deficit in two cultivars (''H2'' and ''660'') of AM treated macadamia (Macadamia tetraphylla L.) plants. AM treatment significantly improved the growth in macadamia plants that have been subjected to water deficit (7 % soil water content) for 14 days. Leaf water content (LWC) and maximum quantum yield of PSII (F v /F m ) in AM-associated plants were maintained better than those in the control (well-watered) plants. A positive correlation was observed between LWC and F v /F m in ''H2'' cultivar. AM treatment enhanced proline and soluble sugar content in ''H2'' cultivar under water deficit stress. In contrast, only soluble sugars were accumulated in the AMassociated plants of ''660'' cultivar under water deficit stress. The study concludes that soluble sugars and proline are involved as key signals of osmoregulation defense response, improve water relation in plant tissues, and thereby resulting in improved growth in AM-associated macadamia plants.

Mycorrhizal Fungi to Alleviate Drought Stress on Plant Growth

“…The colonization of roots by AM fungi in various plant species induces proline accumulation when water is limiting Azcón et al 1996;Goiochea et al 1998;Yooyongwech et al 2013). The enhanced accumulation of proline in these studies was linked to AM-induced drought resistance with proline acting as osmoprotectant.…”

“…Recent reports have indicated that AM symbiosis under drought conditions enhances the photochemical efficiency of photosystem II, given by Fv/Fm, assessed by chlorophyll fluorescence in rice plants (Ruiz-Sánchez et al 2011) and in woody tree nut species (Yooyongwech et al 2013). Such results indicate the improved performance of the photosynthetic machinery and the absence of photoinhibition when mycorrhizal plants were exposed to water deficit.…”

“…Several studies have reported the accumulation of carbohydrates when plants are subjected to water stress in both woody species such as Citrus (Wu and Xia 2006) and Macadamia cultivars (Yooyongwech et al 2013) and in herbaceous species such as lettuce cultivars (Baslam and Goicoechea 2012) and pistachio (Abbaspour et al 2012). Carbohydrate accumulation in these studies was correlated with improved plant performance under drought stress, but the leaf osmotic potential was not evaluated; so correlating changes in carbohydrate levels with differential capacities of osmoregulation in mycorrhizal plants was thus not possible.…”

Insights On the Impact of Arbuscular Mycorrhizal Symbiosis On Tomato Tolerance to Water Stress

“…5A). In the presence of AM symbiosis and upon WS conditions, the content of Pro was reported to be either higher (Ruíz-Sánchez et al, 2011;Abbaspour et al, 2012;Yooyongwech et al, 2013) or lower Bhosale and Shinde, 2011;Zou et al, 2013;Wang et al, 2014;Hazzoumi et al, 2015) than in control plants. Our results, showing a higher content of Pro in AM+ plants during WS with respect to control plants, could suggest a better resistance of colonized plants to WS.…”

Effect of Bioinoculants on the Quality of Crops

“…In the case of micropropagated hazelnut plants, colonization with AMF improves growth rather than survival (Mirabelli et al 2009). Drought tolerance of Macadamias improves when mycorrhized (Yooyongwech et al 2013). Similarly, we could not find any information concerning the effect of PGPR on the quality of O. europaea fruits; actually, the only report concerns the rooting induction of some auxin-producing bacteria on olive cuttings (Montero-Calasanz et al 2013).…”