Background: Nitrogen (N) is a major element and fundamental constituent of grain yield. N fertilizer plays an essential role in the roots, shoots, and leaves of crop plants. Here, we obtained two N-sensitive potato cultivars. Results: The plants were cultivated in the pots using N-deficient and N-sufficient conditions. Crop height, leaf chlorophyll content, dry matter, and N-accumulation significantly decreased under N-deficient conditions. Furthermore, we performed a comprehensive analysis of the phenotype and transcriptome, GO terms, and KEGG pathways. We used WGCNA of co-expressed genes, and 116 differentially expressed hub genes involved in photosynthesis, nitrogen metabolism, and secondary metabolites to generate 23 modules. Among those modules, six NRT gene families, four pigment genes, two auxin-related genes, and two energy-related genes were selected for qRT-PCR validation. Conclusions: Overall, our study demonstrates the co-expressed genes and potential pathways associated with N transport and accumulation in potato cultivars’ roots, shoots, and leaves under N-deficient conditions. Therefore, this study provides new ideas to conduct further research on improving nitrogen use efficiency in potatoes.

With the intensifying global warming trend, extreme heat and drought are becoming more frequent, seriously impacting potato yield and quality. To maintain sustainable potato production, it is necessary to breed new potato varieties that are adaptable to environmental changes and tolerant to adversity. Despite its importance, there is a significant gap in research focused on the potential mechanisms of potato resistance to abiotic stresses like drought and high temperatures. This article provides a comprehensive review of the recent research available in academic databases according to subject keywords about potato drought tolerance and high temperature tolerance with a view to providing an important theoretical basis for the study of potato stress mechanism and the selection and breeding of potato varieties with drought and high-temperature resistance. The suitable relative soil moisture content for potato growth and development is 55% to 85%, and the suitable temperature is 15 °C to 25 °C. The growth and development of potato plants under drought and high-temperature stress conditions are inhibited, and plant morphology is altered, which affects the process of potato stolon formation, tuberization and expansion, ultimately leading to a significant reduction in potato tuber yields and a remarkable degradation of the market grade of tubers, the specific gravity of tubers, and the processing quality of tubers. In addition, stress also adversely affects potato physiological and biochemical characteristics, such as reduction in root diameter and leaf area, decrease in net photosynthetic rate of leaves, production of reactive oxygen species (ROS), and increase in membrane lipid peroxidation. In addition, various types of genes and transcription factors are involved in the response to drought and heat at the molecular level in potato. This paper illustrates the effects of stress on potato growth and development and the molecular mechanisms of potato response to adversity in detail, which is intended to reduce the damage caused by drought and high temperature to potato in the context of global warming and frequent occurrence of extreme weather to ensure potato yield and quality and to further safeguard food security.

Introduction: Potato (Solanum tuberosum L.), as an important food crop on the Qinghai-Tibet Plateau, is prone to low temperature and frost damage during the seedling stage, causing economic losses for farmers.Methods: In this study, metabolome and transcriptome analyses were conducted on the leaves of Atlantic (cold-resistant) and KY140 (cold-sensitive) potato varieties following exposure to cold stress (CS). Results: After CS, 298 and 195 differentially accumulated metabolites (DAMs) were identified in Atlantic and KY140, respectively, with 124 common DAMs, including lipids, flavonoids, alkaloids, organic acids, amino acids and their derivatives, nucleotides and their derivatives, lignans and coumarins, phenolic acids, and terpenoids. A total of 6928 and 2428 differentially expressed genes(DEGs) were identified in Atlantic and KY140, respectively, with 1131 common DEGs. Joint analysis of DAMs and DEGs, “flavonoid-related metabolism,” “lipid metabolism,” and “amino acid metabolism” were plotted. Cinnamic acid, caffeic acid, naringenin, and γ-aminobutyric acid (GABA) might participate in the regulation of potato resistance to CS. The genes StPAL(Soltu.Atl.09_2G005110) and StGAD(Soltu.Atl.11_3G000340) encode enzymes responsible for the biosynthesis of cinnamic acid and GABA, respectively, suggesting their involvement in the regulation of cold resistance in potato. Discussion: Our results provided novel insights into the molecular mechanisms underlying cold resistance in potato.

The red coleoptile trait can help monocotyledonous plants withstand stresses, and key genes responsible for the trait have been isolated from Triticum aestivum, Triticum urartu, and Triticum monococcum, but no corresponding research has been reported for Aegilops tauschii. In this research, transcriptome analysis was performed to isolate the candidate gene controlling the white coleoptile trait in Ae. tauschii. There were 5348 upregulated, differentially-expressed genes (DEGs) and 4761 downregulated DEGs in red coleoptile vs. white coleoptile plants. Among these DEGs, 12 structural genes and two transcription factors involved in anthocyanin biosynthesis were identified. The majority of structural genes showed lower transcript abundance in the white coleoptile of accession ‘As77’ than in the red coleoptile of accession ‘As60’, which implied that transcription factors related to anthocyanin biosynthesis could be the candidate genes. The MYB and MYC transcription factors AetMYB7D and AetMYC1 were both isolated from Ae. tauschii accessions ‘As60’ and ‘As77’, and their transcript levels analyzed. The coding sequence and transcript level of AetMYB7D showed no difference between ‘As60’ and ‘As77’. AetMYC1p encoded a 567-amino acid polypeptide in ‘As60’ containing the entire characteristic domains, bHLH-MYC_N, HLH, and ACT-like, belonging to the gene family involved in regulating anthocyanin biosynthesis. AetMYC1w encoded a 436-amino acid polypeptide in ‘As77’ without the ACT-like domain because a single nucleotide mutation at 1310 bp caused premature termination. Transient expression of AetMYC1p induced anthocyanin biosynthesis in ‘As77’ with the co-expression of AetMYB7D, while AetMYC1w could not cause induced anthocyanin biosynthesis under the same circumstances. Moreover, the transcript abundance of AetMYC1w was lower than that of AetMYC1p. AetMYC1 appears to be the candidate gene controlling the white coleoptile trait in Ae. tauschii, which can be used for potential biotech applications, such as producing new synthetic hexaploid wheat lines with different coleoptile colors.

Chloroplasts are critical organelles for photosynthesis and play significant roles in plant growth and metabolism. High temperature is one of abiotic stresses affecting the growth and development of plants, involving chlorophyll biosynthesis and chloroplast development. It is well known that the methyl erythritol 4-phosphate (MEP) pathway is vital to photosynthesis and plant growth, and 1-deoxy-D-xylulose-5-phosphate synthase (DXS) is the enzyme that catalyze the first step of the MEP pathway. Although DXS has been widely studied in microbes and plants, no DXS gene has been identified in rice. Here, a novel thermo-sensitive chlorophyll-deficient 5 (tscd5) mutant was isolated in rice with decreased chlorophyll contents, impaired chloroplasts, and albino leaves at high temperature (35 °C). Fine mapping and DNA sequencing of TSCD5 found a missense mutation (G to A) in the sixth exon of LOC_Os05g33840 in tscd5. The TSCD5 gene encodes a 1-deoxy-D-xylulose-5-phosphate synthase 1 (OsDXS1) localized in chloroplast. Complementation tests and overexpression assay demonstrated that the mutation in LOC_Os05g33840 caused the tscd5 phenotype. qRT-PCR of TSCD5 showed it was constitutively expressed in all tissues, and its transcript amounts were reduced in tscd5 under high temperature. Here, TSCD5 is verified to be crucial to chloroplast development under high temperature in rice, which may facilitate the elucidation of the molecular mechanisms which underlie acclimation to high temperature stress in plants.