Symbiotic compatibility between Oryza sativa cultivars and arbuscular mycorrhizal fungi genotypes affects rice growth and mycorrhiza-induced resistance to Xanthomonas oryzae pv oryzae

Abstract

Background Arbuscular Mycorrhizal Fungi (AMF) belong to the Glomeromycota clade and can form root symbioses with 80% of Angiosperms, including agronomically-interesting crops species such as wheat, maize and rice. By increasing nutrient availability, uptake and soil anchoring of plants, AMF can improve plant’s growth and tolerance to abiotic stresses. AMF can also reduce symptoms and pathogen load on infected plants, both locally and systemically, through a phenomenon called Mycorrhiza-Induced Resistance (MIR). There is scarce information on rice mycorrhization, despite the high potential of this symbiosis in a context of sustainable water management in rice production systems. Results We studied the symbiotic compatibility (global mycorrhization & arbuscules intensity) and MIR phenotypes between six rice cultivars from two subspecies (indica: IR64 & Phka Rumduol; japonica: Nipponbare, Kitaake, Azucena & Zhonghua 11) and three AMF genotypes (Funneliformis mosseae FR140, Rhizophagus irregularis DAOM197198 & R. intraradices FR121). The impact of mycorrhization on rice growth and defence response to Xanthomonas oryzae pv. oryzae (Xoo) infection was recorded via both phenotypic indexes and rice marker gene expression studies. All three AMF genotypes colonise the roots of all rice varieties, with clear differences in symbiotic compatibility depending on the combination under study. AMF interaction induced either neutral, beneficial, or negative effects on rice growth, but only neutral to beneficial effects on the extent of Xoo symptoms on leaves. R. irregularis DAOM197198 proved to be the most colonising AMF in terms of global mycorrhization and arbuscule intensities, inducing rice growth and reducing symptoms caused by Xoo in all rice varieties. Transcriptomic analyses by RT-qPCR on leaves of two rice cultivars contrasting in their interactions with AMF, shows two different pattern of response both on growth and defence marker genes, that can be related to their phenotypic responses. Conclusions The symbiotic compatibility between rice and AMF depends both on plant cultivar and AMF genotypes. Under our conditions, it drives beneficial, neutral, or negative effects on rice growth, and in some cases, MIR phenotypes after Xoo leaf infection. The interactions between rice and AMF genotypes drive different transcriptomic responses, shedding light on molecular markers of compatibility at the leaf level.

Synergic Effects of Salinity and Rhizoctonia solani (Kuhn) Infection on Growth and Yield Attributes of Rice (Oryza sativa L.)

“…Hence, this investigation endeavors to bridge this knowledge gap by examining the combined effects of salinity stress and R. solani infection on crucial growth parameters and yield components across diverse rice varieties. The findings will be instrumental in ensuring food security globally and agricultural sustainablity in the face of environmental challenges (Abu-Ria et al, 2023;Guigard et al, 2023;Taha et al, 2023).…”