Arbuscular mycorrhizal fungi impact on yield attributes, protein quantity and quality in bread wheat (Triticum aestivum L.) grown under drought stress.

Drought is increasingly becoming a production constraint in wheat world-wide. Arbuscular mycorrhizal fungi (AMF)-bread wheat symbiosis has been shown to improve the tolerance under drought stress. The objective of this study was to determine the effects of AMF inoculation on yield attributes (spike number per plant, spike weight per plant, number of grains per spike, grain weight per spike and 1000 grain weight) and protein quantity and quality in two bread wheat cultivars (PAN3497 and SST806) grown under drought stress. Plant growth was significantly reduced due to drought stress in both cultivars. Shoot dry weight was significantly increased (23%) due to AMF inoculation in SST806. AMF inoculation caused a further significant increase of protein content in both cultivars (10.70% and 13.42% in PAN3497 and SST806, respectively). Low molecular weight (LMW) glutenin was significantly decreased in PAN3497 under drought stress. However, the monomeric proteins were significantly increased by drought and/or a combination of drought and AMF inoculation in both cultivars. In cultivar SST806, significant reduction of polymeric protein was observed due to application of both AMF (6%) and a combination of AMF with drought stress (4%). Regarding the two-dimensional separation of the gluten proteins, drought had the largest effect on protein spots, with AMF causing up-regulation of only some spots. SST806 was generally more drought tolerant than PAN3497. [ABSTRACT FROM AUTHOR]