Plants tolerate cold stress by regulating gene networks controlling cellular and physiological traits to modify growth and development. Transcription factor (TF)-directed regulation of transcription within these gene networks is key to eliciting appropriate responses. Identifying TFs related to cold tolerance contributes to cold-tolerant crop breeding. In this study, a comparative transcriptome analysis was carried out to investigate global gene expression of entire TFs in two peanut varieties with different cold-tolerant abilities. A total of 87 TF families including 2328 TF genes were identified. Among them, 445 TF genes were significantly differentially expressed in two peanut varieties under cold stress. The TF families represented by the largest numbers of differentially expressed members were bHLH (basic helix—loop—helix protein), C2H2 (Cys2/His2 zinc finger protein), ERF (ethylene-responsive factor), MYB (v-myb avian myeloblastosis viral oncogene homolog), NAC (NAM, ATAF1/2, CUC2) and WRKY TFs. Phylogenetic evolutionary analysis, temporal expression profiling, protein–protein interaction (PPI) network, and functional enrichment of differentially expressed TFs revealed the importance of plant hormone signal transduction and plant-pathogen interaction pathways and their possible mechanism in peanut cold tolerance. This study contributes to a better understanding of the complex mechanism of TFs in response to cold stress in peanut and provides valuable resources for the investigation of evolutionary history and biological functions of peanut TFs genes involved in cold tolerance.

Changes in the canopy microclimate in intercropping systems, particularly in the light environment, have important effects on the physiological characteristics of photosynthesis and yield of crops. Although different row ratio configurations and strip widths of dwarf crops in intercropping systems have important effects on canopy microclimate, little information is available on the effects of intercropping on chlorophyll synthesis and photosynthetic physiological properties of dwarf crops. A 2-year field experiment was conducted in 2019 and 2020, with five treatments: sole maize (SM), sole peanut (SP), four rows of maize intercropping with eight rows of peanut (M4P8), four rows of maize intercropping with four rows of peanut (M4P4), and four rows of maize intercropping with two rows of peanut (M4P2). The results showed that the light transmittance [photosynthetically active radiation (PAR)], photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (Gs) of intercropped peanut canopy were reduced, while the intercellular carbon dioxide concentration (Ci) was increased, compared with SP. In particular, the M4P8 pattern Pn (2-year mean) was reduced by 5.68%, 5.33%, and 5.30%; Tr was reduced by 7.41%, 5.45%, and 5.95%; and Gs was reduced by 8.20%, 6.88%, and 6.46%; and Ci increased by 11.95%, 8.06%, and 9.61% compared to SP, at the flowering needle stage, pod stage, and maturity, respectively. M4P8 improves the content of chlorophyll synthesis precursor and conversion efficiency, which promotes the utilization efficiency of light energy. However, it was significantly reduced in M4P2 and M4P4 treatment. The dry matter accumulation and pod yield of peanut in M4P8 treatment decreased, but the proportion of dry matter distribution in the late growth period was more transferred to pods. The full pod number decreases as the peanut row ratio decreases and increases with year, but there is no significant difference between years. M4P8 has the highest yield and land use efficiency and can be used as a reference row ratio configuration for maize–peanut intercropping to obtain relatively high yield benefits.

Rotational strip intercropping (RSI) of cereals and legumes has been developed and widely carried out to alleviate continuous cropping obstacles, to control erosion and to improve field use efficiency. In this study, a four-year fixed-field experiment was carried out in northeast China with three treatments: continuous cropping of maize, continuous cropping of peanuts and rotational strip intercropping of maize and peanut. The results show that crop rotation improved the main-stem height, branch number, lateral branch length, and yield and quality of peanuts; the yield was the highest in 2018, when it was increased by 39.5%. RSI improved the contents of total N, available N, total P, available P, total K and available K; the content of available N was the highest in 2018, with an increase of 70%. Rhizosphere soil urease and catalase activities were significantly increased and were the highest in 2017, reaching 183.13% and 91.21%, respectively. According to a high-throughput sequencing analysis, the rhizosphere soil bacterial richness and specific OTUs decreased in peanut rhizosphere soil, while the fungal increased. There were differences in the bacterial and fungal community structures; specifically, the abundance of Acidobacteria and Planctomycetes increased among bacteria and the abundance of beneficial microorganisms such as Ascomycota increased among fungi. In conclusion, rotational strip intercropping of maize and peanut increased the yield and quality of peanuts and conducive to alleviating the obstacles facing the continuous cropping of peanuts. Among then, soil physicochemical properties, enzyme activity and microbial diversity were significantly affected the yield of peanut.

The global expansion of rapeseed seed quality has been focused on maintaining glucosinolate (GSL) and erucic acid (EA) contents. However, the influence of seed GSL and EA contents on the germination process under drought stress remains poorly understood. Herein, 114 rapeseed accessions were divided into four groups based on GSL and EA contents to investigate their performance during seed imbibition under drought stress. Our results revealed significant variations in seed germination-related traits, particularly with higher GSL and EA, which exhibited higher germination % (G%) and lower mean germination time (MGT) under drought stress conditions. Moreover, osmoregulation, enzymatic system and hormonal regulation were improved in high GSL and high EA (HGHE) versus low GSL and low EA (LGLE) seeds, indicating the essential protective role of GSL and EA during the germination process in response to drought stress. The transcriptional regulation mechanism for coordinating GSL–EA-related pathways in response to drought stress during seed imbibition was found to involve the differential expression of sugar metabolism-, antioxidant-, and hormone-related genes with higher enrichment in HGHE compared to LGLE seeds. GO enrichment analysis showed higher variations in transcription regulator activity and DNA-binding transcription factors, as well as ATP and microtubule motor activity in GSL–EA-related pathways. Furthermore, KEGG analysis identified cellular processes, environmental information processing, and metabolism categories, with varied gene participation between GSL, EA and GSL–EA-related pathways. For further clarification, QY7 (LGLE) seeds were primed with different concentrations of GSL and EA under drought stress conditions. The results showed that 200 μmol/L of GSL and 400 μmol/L of EA significantly improved G%, MGT, and seedling fresh weight, besides regulating stress and fatty acid responsive genes during the seed germination process under drought stress conditions. Conclusively, exogenous application of GSL and EA is considered a promising method for enhancing the drought tolerance of LGLE seeds. Furthermore, the current investigation could provide a theoretical basis of GSL and EA roles and their underlying mechanisms in stress tolerance during the germination process.

Potassium (K) is an essential macronutrient that plays an important role in abiotic stress tolerance. A pot experiment was carried out to identify the potential role of potassium fertilizer in alleviating salt stress in peanut. The results sho...