Monotonous cucumber double-cropping systems under plastic greenhouse vegetable cultivation (PGVC) previously intensified by long-term anthropogenic activities and manipulative treatments leads to a crop productivity reduction and soil biota disturbances. In this study, the role of the indigenous arbuscular mycorrhizal strain (AM: Glomus versiforme L.) and organic substrate (GS: Garlic stalk) application were assessed for plant microbe interaction and crop productivity feedback in a greenhouse (2016–2018) under a cultivated Anthrosol characterized as a replanted degraded soil. We found that repetitively adding AM inocula with organic substrates (GS) improved the cucumber growth and physiology. The useful trait of AM symbiosis with C-amended organic substrates preferentially manifested as increased root colonization, hyphal density proliferation, AM sporulation, root activity, and suppressed Fusarium incidence. The post AM development further prevailed the synergistic interaction, and the co-inoculation effect resulted in an increase in fruit nutrition uptake, seasonal cucumber yield and fruit quality attributes. Illumina MiSeq analysis of the 18S rRNA gene amplicons revealed that the dominant AM genera that are particularly enriched with the Glomus taxon may be important ecological drivers associated with plant productivity and fruit quality characteristics. These results suggest that the AM-organic substrate association might be a pragmatic option for use as an economic and efficient biological resource and as a newly-sustainable plant microbe mediator to enhance the regional ecosystem services and plant productivity of the anthropogenic PGVC of this region.

Garlic has a strong ability of selenium (Se) accumulation and is one of the best target crops for Se biofortification. Arbuscular mycorrhizal fungi (AMF) inoculation might enhance the nutritional qualities and the absorption ability of exogenous Se in plants. However, little is known about the exogenous Se application and AMF inoculation on garlic. Here, we evaluated the effects of different concentrations of exogenous Se on the growth, nutritional quality, and selenium enrichment of garlic. The results demonstrated that significantly higher Se content of garlic bulb was found in exogenous Se treated plants, and the Se accumulation was improved with the increasing of Se supply. Low application of exogenous Se appreciably improved the yield and the contents of soluble sugar and allicin in garlic bulbs, but the opposite was observed at high Se concentration. Furthermore, AMF inoculation significantly reduced the inhibition effect of high concentration Se on garlic. AMF supply was effective in improving the growth and nutritional indicators of garlic, which promoted the exogenous Se utilization rate when combined with 10 mg/L exogenous Se treatment. The results will provide a more theoretical basis for the production of high-quality selenium enrichment garlic.

Citric acid (CA) plays a crucial role as a fruit flavor enhancer and serves as a mediator in multiple metabolic pathways in tomato fruit development. Understanding factors influencing CA metabolism is essential for enhancing fruit flavor and CA-mediated biological processes. The accumulation of CA, however, is influenced by a complex interplay of genetic and environmental factors, leading to challenges in accurately predicting and regulating its levels. In this study, we conducted a genome-wide association study (GWAS) on CA, employing six landmark models based on genome-wide variations including structural variants, insertions and deletions, and single nucleotide polymorphisms. The identification of 11 high-confidence candidate genes was further facilitated by leveraging linkage disequilibrium and causal variants associated with CA. The transcriptome data from candidate genes were examined, revealing higher correlations between the expression of certain candidate genes and changes in CA metabolism. Three CA-associated genes exerted a positive regulatory effect on CA accumulation, while the remaining genes exhibited negative impacts based on gene cluster and correlation analyses. The CA content of tomatoes is primarily influenced by improvement sweeps with minimal influence from domestication sweeps in the long-term breeding history, as evidenced by population differentiation and variants distribution. The presence of various causal variants within candidate genes is implicated in the heterogeneity of CA content observed among the tomato accessions. This observation suggests a potential correlation between the number of alternative alleles and CA content. This study offers significant function-based markers that can be utilized in marker-assisted breeding, thereby enhancing their value and applicability.

The AP2/ERF family constitutes one of the largest groups of transcription factors in the Solanaceae. AP2/ERF contributes to various plant biological processes, including growth, development, and responses to various stresses. The origins and functional diversification of AP2/ERF within the Solanaceae family remain poorly understood, primarily because of the complex interactions between whole-genome duplications (WGDs) and tandem duplications. In this study, a total of 1282 AP2/ERF proteins are identified from 7 Solanaceae genomes. The amplification of AP2/ERF genes was driven not only by WGDs but also by the presence of clusters of tandem duplicated genes. The conservation of synteny across different chromosomes provides compelling evidence for the impact of the WGD event on the distribution pattern of AP2/ERF genes. Distinct expression patterns suggest that the multiple copies of AP2/ERF genes evolved in different functional directions, catalyzing the diversification of roles among the duplicated genes, which was of great significance for the adaptability of Solanaceae. Gene silencing and overexpression assays suggest that ERF-1 members’ role in regulating the timing of floral initiation in C. annuum. Our findings provide insights into the genomic origins, duplication events, and function divergence of the Solanaceae AP2/ERF.