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MYB-CC transcription factors (TFs) are essential for plant growth and development. Members of the MYB-CC subfamily with long N terminal domains, such as phosphate starvation response 1 (PHR1) or PHR1-like TFs, have well documented functions, while those with short N terminal domains remain less understood. In this study, we identified a nodule specific MYB-CC transcription factor 1 (GmPHR1) in soybean that is different from other canonical PHR family genes in that GmPHR1 harbors a short N terminal ahead of its MYB-CC domain and was highly induced by rhizobium infection. The overexpression of GmPHR1 dramatically increased the ratio of deformed root hairs, enhanced subsequent soybean nodulation, and promoted soybean growth in pot experiments. The growth promotion effects of GmPHR1 overexpression were further demonstrated in field trails in which two GmPHR1-OE lines yielded 10.78% and 8.19% more than the wild type line. Transcriptome analysis suggested that GmPHR1 overexpression led to global reprogramming, with 749 genes upregulated and 279 genes downregulated, especially for genes involved in MYB transcription factor activities, root growth, and nutrient acquisition. Taken together, we conclude that GmPHR1 is a key gene involved in the global regulation of nodulation, root growth, and nutrient acquisition in soybeans, and is thus a promising candidate gene to target for soybean yield enhancement. [ABSTRACT FROM AUTHOR]

Plant microbiota are of great importance for host nutrition and health. As a C4 plant species with a high carbon fixation capacity, sugarcane also associates with beneficial microbes, though mechanisms underlying sugarcane root-associated community development remain unclear. Here, we identify microbes that are specifically enriched around sugarcane roots and report results of functional testing of potentially beneficial microbes propagating with sugarcane plants. First, we analyzed recruitment of microbes through analysis of 16S rDNA enrichment in greenhouse cultured sugarcane seedlings growing in field soil. Then, plant-associated microbes were isolated and assayed for beneficial activity, first in greenhouse experiments, followed by field trials for selected microbial strains. The promising beneficial microbe SRB-109, which quickly colonized both roots and shoots of sugarcane plants, significantly promoted sugarcane growth in field trials, nitrogen and potassium acquisition increasing by 35.68 and 28.35%, respectively. Taken together, this report demonstrates successful identification and utilization of beneficial plant-associated microbes in sugarcane production. Further development might facilitate incorporation of such growth-promoting microbial applications in large-scale sugarcane production, which may not only increase yields but also reduce fertilizer costs and runoff. [ABSTRACT FROM AUTHOR]

Root‐associated microbes are critical for plant growth and nutrient acquisition. However, scant information exists on optimizing communities of beneficial root‐associated microbes or the mechanisms underlying their interactions with host plants. In this report, we demonstrate that root‐associated microbes are critical influencers of host plant growth and nutrient acquisition. Three synthetic communities (SynComs) were constructed based on functional screening of 1,893 microbial strains isolated from root‐associated compartments of soybean plants. Functional assemblage of SynComs promoted significant plant growth and nutrient acquisition under both N/P nutrient deficiency and sufficiency conditions. Field trials further revealed that application of SynComs stably and significantly promoted plant growth, facilitated N and P acquisition, and subsequently increased soybean yield. Among the tested communities, SynCom1 exhibited the greatest promotion effect, with yield increases of up to 36.1% observed in two field sites. Further RNA‐seq implied that SynCom application systemically regulates N and P signaling networks at the transcriptional level, which leads to increased representation of important growth pathways, especially those related to auxin responses. Overall, this study details a promising strategy for constructing SynComs based on functional screening, which are capable of enhancing nutrient acquisition and crop yield through the activities of beneficial root‐associated microbes. [ABSTRACT FROM AUTHOR]