Arbuscular Mycorrhizal Fungi Alleviate Low Phosphorus Stress in Maize Genotypes with Contrasting Root Systems

Abstract

Soil available phosphorus (P) is one of the main factors limiting plant growth and yield. This study aimed to determine the role of arbuscular mycorrhizal fungi (AMF) in P-use efficiency in two maize genotypes with contrasting root systems in response to low P stress. Maize genotypes small-rooted Shengrui 999 and large-rooted Zhongke 11 were grown in rhizoboxes that were inoculated with or without AMF (Funneliformis mosseae) under low P (no added P) or optimal P (200 mg kg−1) for 53 days. Low P stress significantly inhibited shoot and root growth, photosynthesis, tissue P content, and root P concentration in both genotypes. Shengrui 999 was more tolerant to P stress with less reduction of these traits compared to Zhongke 11. Shengrui 999 had a higher AMF infection rate than Zhongke 11 at both P levels. Under P deficit, inoculation with AMF significantly promoted plant growth and P uptake in both genotypes with more profound effects seen in Zhongke 11, whilst Shengrui 999 was more dependent on AMF under optimal P. Low P stress inhibited the growth and physiological attributes of both genotypes. The small-rooted Shengrui 999 was more tolerant to low P than Zhongke 11. Inoculation with AMF alleviates low P stress in both genotypes with a more profound effect on Zhongke 11 at low P and on Shengrui 999 at high P conditions.

Evidence that a common arbuscular mycorrhizal network alleviates phosphate shortage in interconnected walnut sapling and maize plants

“…In this respect, it has been proposed that the regulation of the abundance of Pi transporters in the periarbuscular membrane is probably more dependent on post-transcriptional and post-translational regulation events (Grace et al, 2009;Smith et al, 2011;Walder et al, 2015). As previously observed in maize plants (Tian et al, 2013;Polcyn et al, 2019;Liang et al, 2022), increasing Pi fertilization did not significantly decrease mycorrhizal colonization, suggesting that phosphate inhibition of internal mycorrhization may not be a general paradigm, depending on host and fungal genotypes (Peña Venegas et al, 2021).…”

Phosphorus deficiency tolerance in sorghum

“…In contrast to the severe inhibition of leaf expansion under P deficiency, protein and chlorophyll concentrations per unit leaf area are less affected. Low P stress significantly inhibited shoot and root growth, photosynthesis, tissue P content, and root P concentration in both tolerant and sensitive genotypes of maize, in which the tolerant genotype to P stress showed a less reduction of these traits compared to the sensitive ones (Liang et al, 2022). Phosphorus deficiency in soil inhibits N2 fixation (Lazali and Drevon, 2021), as shown by the decrease in legume production, due to strong impact of phosphorus deficiency on the growth and survival of both rhizobia and host plant.…”

“…Several studies have revealed the symbiotic mechanism between plants and mycorrhizae and/or soil microbes as a strategy to cope with P deficiency stress (Hiradate et al, 2007;Niu et al, 2013;Kariman et al 2014;Mattos et al, 2020;Liang et al, 2022). Phosphorus is mainly absorbed and utilized by plant roots through phosphate transport protein carriers.…”

“…Phosphorus is mainly absorbed and utilized by plant roots through phosphate transport protein carriers. However, most of the P in the soil is in the form of insoluble organic P, which is also characterized by high adsorption and low mobility, so P often becomes scarce in the soil (Liang et al, 2022). According to Kariman et al (2014), several plant species have mechanisms to increase P extraction from the soil.…”