Fungal endophytes enhance wheat heat and drought tolerance in terms of grain yield and second-generation seed viability

Abstract

Aims: We evaluated the impact of fungal endophyte symbiosis on the growth, ecophysiological and reproductive success of wheat exposed to heat and drought. Methods and Results: The resistance of pot-grown wheat to heat or drought stress was measured by quantifying efficiency of photosystem II (F v /F m ), plant height, average seed weight (ASW), total seed weight (TSW), water-use efficiency (WUE) as well as time to 50% germination and percentage germination of second-generation seeds produced under heat stress, drought stress or wellwatered conditions. The endophytic fungi tested increased wheat tolerance for drought and heat. Endophyte SMCD 2206 was the most beneficial, followed by SMCD 2210 and 2215. Surprisingly, second-generation seeds produced by drought-stressed wheat colonized by SMCD 2206, 2210 or 2215 had decreased WUE relative to those produced by endophyte-free, drought-stressed plants. However, these seeds germinated more rapidly than those produced by endophyte-free, stressed parental plants. Conclusions:The tested consortium of endophytes has the potential to improve wheat adaptation to heat and drought. Significance and Impact of the Study: The capacity of endophytes to increase wheat tolerance for abiotic stress and to improved germination in endophytefree second-generation seeds arising from stressed plants could be applicable to agriculture. The mechanisms by which intergenerational endophyte-mediated affects occurs warrant further research.

Diversity and distribution of the endophytic fungal community in eucalyptus leaves

“…The strong dominance of some fungal groups (Table 4) indicates that they can play a relevant role in plant physiology. Fungal species can produce a wide variety of growth regulators, such as gibberellins (GAs), abscisic acid (ABA), and auxins (IAA) (You et al, 2012), and they can also confer tolerance to adverse biotic and abiotic factors (Hubbard et al, 2014).…”

Seed endosymbiosis: a vital relationship in providing prenatal care to plants

“…In fact, an extreme example is Cypripedium (Lady slippers) terrestrial orchids, which seeds obligately depending on mutualistic endophytic fungi for germination (Vujanovic et al 2000). By moderating the physiological stress response via mycovitality Hubbard et al 2012), the endophytic fungi improve wheat seed germination stages under drought and heat, yielding wheat plants with significantly improved agricultural traits (Hubbard et al 2014b).…”

“…Hubbard et al (2014b) demonstrated that mycovitality improves wheat's seed germination (Baskin and Baskin 2014), overall host productivity, and resilience against drought and heat. Further studies have shown that these advantages are transmitted to the offspring, thus potentially bringing about a plant epigenetic modification (Hubbard et al 2014a).…”

“…Interestingly, it also does so during the seedling growth stages (Sherameti et al 2008;Alikhani et al 2013). Mycovitality is a symbiotic, seed-fungal endophyte relationship ) capable of enhancing seed vigor (Vujanovic et al 2000), energy of germination, and hydrothermal time of germination by better seedling water-use efficiency, in addition to an improved resilience to environmental stresses such as drought and heat (Hubbard et al 2012;Hubbard et al 2014b). Mycovitalism is unique to symbiotic endophytes (Abdellatif et al 2009).…”

Microbial Symbionts: A Potential Bio-Boom

“…Many researchers have reported the discovery of microbial symbionts from wild and crop plants. Several of these symbionts show positive effects on crop productivity and stress tolerance of tomato, wheat, rice, barley, and other crops mainly under green house conditions [40][41][42][43]. Microbial symbionts can increase plant productivity and stress tolerance via various mechanisms.…”