A large number of studies have shown that different miRNAs are involved in different stress conditions and play an extremely important role in plant growth and development. We screened for differential miRNAs between Yanshu4 and Atlantic in roots and leaves at seedling and budding stages, and our analysis found that stu-miR396-5p, stu-miR408b-3p_R-1, stu-miR3627-3p, stu-miR482a-3p, stu-miR8036-3p, stu-miR482a-5p, stu-miR827-5p, stu-miR156a_L-1, stu-miR827-3p, stu-miR172b-5p, stu-miR6022-p3_7, stu-miR398a-5p, stu-miR166c -5p_L-3 were significantly different.
Researchers found that miR396 is directly involved in the regulation of plant metabolism and plant growth and development, such as water stress, temperature stress, salt stress, oxidation process, fatty acid metabolism, root tip growth and development and bacterial infections. The study found that miR396-GRF plays an important role in regulating the response to different nitrogen forms. In lettuce,LSA-miR396 affects the content of different nitrogen forms by regulating LsaGRFs during leaf growth. We found that differential miR396-5p was highly sensitive to N stress, and stu-miR396-5p was down-regulated in both seedling leaves and roots and budding leaves and roots of large Atlantic, in seedling leaves and budding roots of Yanshu4 and in It was up-regulated in the roots of seedlings and leaves at the budding stage, which is consistent with the previous study. Fischer studies on the regulation of miRNAs expression in plants revealed that miR396 was also found to be down-regulated under nitrogen-deficient conditions. We found that stu-miR398a-5p was up-regulated in leaves at seedling and budding stage and down-regulated in roots at seedling and budding stage under two N stresses. In Atlantic, stu-miR398a-5p was up-regulated in leaves and roots at seedling stage and budding stage. The expression of stu-miR408b-3p_R-1 was up-regulated in leaves and roots at seedling stage and budding stage, which indicated that stu-miR408b-3p_R-1 was highly responsive to N stress. Several studies have found that MiR160 is highly responsive to N and S deficiency. Under N starvation conditions, the expression of miR169, miR171, miR398, miR399, miR408, miR827, and miR857 was repressed, whereas the expression of miR160, miR826, miR842, and miR846 was induced. At the same time, it was found that miR156, miR172 and miR398 were responsive to low temperature stress. Based on the research of others, we further clarified the specific expression location and period, which provided some references for future related research. Fischer discovered the regulatory mechanism of miRNA expression under nitrogen deficiency in plants, and found that the expression of miR156 was up-regulated under nitrogen deficiency. Studies have shown that miR156 plays an important role in many metabolic pathways in potato, such as miR156 inhibits the formation of potato tubers. miR156e regulates potato tuber development by regulating the expression of its target gene StPTB6,other studies pointed out that the expression level of potato miR156 is also regulated by photoperiod, and miR156/157 targets SPL transcription factors A study on regulating the polarity of potato flower organs.. We found that stu-miR156a_L-1 was down-regulated in leaves and roots at seedling stage and roots at budding stage under two N stresses. Under two N stresses, the expression of stu-miR156a_L-1 was down-regulated in seedling leaves and sprouting roots of Atlantic, and up-regulated in seedling roots and sprouting leaves, and the expression of stu-miR156_L-1 in leaves of these two types of potatoes was over-fertilized with nitrogen. The expression level was significantly higher under N stress than in non-N treated leaves, suggesting that stu-miR156_L-1 plays an important role in the process of N stress. Its corresponding target gene is the key enzyme gene NRT2.5 in the nitrogen metabolism pathway. The early identification of the NRT family showed that when N is sufficient, family members play an active role in the nitrogen metabolism pathway, while nitrogen deficiency induces potato stress. Therefore, we speculate that stu-miR156a_L-1 may have a regulatory relationship with its target gene NRT2.5, which regulates the nitrogen metabolism pathway of potato, but the specific regulatory mechanism needs to be further explored. Studies indicate that inhibition of miR482 has been shown to inhibit miR482 in potato, tomato and cotton. Effectively inhibit plant infection with pathogenic bacteria. Through the study of two kinds of potatoes, we found that under the two kinds of N stress, with the increase of nitrogen application, the expression levels of stu-miR482a-5p and stu-miR482a-5p showed an upward trend, indicating that miR482a-5p has a sensitive response to different N treatment. The expression of stu-miR482a-3p in Yanshu4 was up-regulated in leaves at seedling stage and roots and leaves at budding stage under two N stresses. The expression of stu-miR482a-3p was down-regulated in leaves and roots at seedling stage and up-regulated in leaves and roots at budding stage in the Atlantic under two N stresses. stu-miR482a-5p was up-regulated in leaves and roots at seedling and budding stages. We initially found that miR482a induced expression changes under N stress, but the specific function of miR482a needs further study. Studies have shown that in potato plants,miR172 is involved in flower and tuber induction signal transduction pathways and a clear link between solute transport and flowering and nodulation induction. other study showed that tomato miR172 targets and regulates the APETALA2 transcription factor SlAP2a to regulate fruit ripening, Ferdous found that miR172,miR396a and miR396c regulate P5CS genes respectively under water stress in barley, thereby regulating proline accumulation and providing molecular evidence for the drought tolerance process in potato. There are also research found that miR172 was significantly expressed in the developmental stage of potato tubers. We found that the expression of stu-miR172b-5p in Atlantic roots was higher than that in leaves at the budding stage under excessive nitrogen application, and the expression of stu-miR172b-5p was up-regulated in Atlantic seedling and budding leaves and roots, but down-regulated in roots at seedling stage. In Yanshu4, stu-miR172b-5p was up-regulated in roots at seedling and shoot stages, but down-regulated in leaves at seedling stage, and was highly sensitive to nitrogen stress. This is similar to the previous conclusions, but its deeper function needs further study. stu-miR827 is mainly involved in biological processes such as ribosome formation, aminoacyl biosynthesis, and plant hormone signal transduction in eukaryotes. Studies have pointed out that miR827 plays a key role in the adaptation of barley to drought tolerance, and MiR827 has a strong induction effect on PI starvation through shoots and roots. We found significant differences in the enlargement of stu-miR827-3p and stu-miR827-5p between the two types of potatoes under N treatment. In Yanshu4, stu-miR827-5p was down-regulated in leaves and up-regulated in roots. The expression of stu-miR827-3p was down-regulated in leaves and roots at seedling stage and in roots at budding stage, but up-regulated in roots at seedling stage. In Atlantic, stu-miR827-5p was up-regulated in roots and down-regulated in leaves at seedling and budding stages. The expression of stu-miR827-3p was down-regulated in leaves and up-regulated in roots at seedling and budding stages. However, we intend to screen out genes closely related to nitrogen metabolism, and their target genes do not include key enzymes in nitrogen metabolism pathways, so we can consider studying from different directions. miR408 is involved in plant growth and stress response, and miR408 can regulate plastid cyanin (PC) by down-regulating target proteins, thereby affecting photosynthesis and ultimately promoting grain yield, revealing that miR408 plays an important role in regulating plant growth and development and plant responses to various abiotic and biotic stresses. Previous studies have shown that overexpression of miR408 can significantly enhance the drought tolerance of chickpeas, while recent studies have shown that functional deficits of miR408 can negatively regulate light-dependent seed germination. We found that stu-miR408b-3p_R-1 was up-regulated in leaves at seedling stage and roots and leaves at budding stage in Yanshu4 under two N stresses, and stu-miR408b-3p_R-1 was up-regulated in leaves and roots at seedling stage and budding stage in Atlantic, which was highly responsive to N stress. We verified the expression of miR408 from a new abiotic stress perspective, providing a new direction for people to further understand this ancient and highly conserved miRNA. Little is known about miR8036. We found that stu-miR8036-3p was up-regulated in leaves and roots at seedling stage and budding stage in Atlantic under two N stresses. In Yanshu4, stu-miR8036-3p was up-regulated in leaves and roots at seedling stage and down-regulated in leaves and roots at budding stage. The specific regulatory mechanism is still unclear, and miRNA, as a relatively blank, needs further study. miR398 is considered to be a kind of miRNA directly related to plant stress regulation network, which regulates plant responses to oxidative stress, water deficit, salt stress, abscisic acid stress, ultraviolet stress, copper and phosphorus deficiency, high sugar and bacterial infection, and has great value for the study of biology and biological stress. Studies have shown that miR398 can enhance SOD activity in wheat roots by regulating the expression of WRKY, thus alleviating non-induced oxidative toxicity in wheat roots. Recent studies have shown that miR398 can alleviate symptoms and accumulation of bamboo mosaic virus by regulating antioxidants. We found that stu-miR398a-5p was up-regulated in leaves and roots at seedling stage and budding stage in Atlantic under two N stresses, and up-regulated in leaves at seedling stage and budding stage in Yanshu4, but down-regulated in roots at seedling stage and budding stage. We studied the regulatory relationship of miR398 from the direction of N stress, which enriched the research content of miR398.
It was found that the relative abundance of Streptococcus tomato and Streptococcus Habrochetti subtypes changed significantly under low temperature stress, which indicated that miR6022 played an important role in cold stress response. Other studies have shown that sly-miR6022 can regulate tomato R gene Cf-9 at post-transcriptional level in tomato. Through the interweaving study of different regulatory networks in potato, it is found that miR6022 participates in regulating the regulatory networks of other miRNAs, revealing that miRNAs are balanced by mutual regulation in developmental signaling, disease symptom development and stress signaling. We found that stu-miR6022-p3_7 was up-regulated in seedling roots in Yanshu4 under two N stresses, and in seedling leaves and bud roots in Atlantic. Our research provides new research ideas on the basis of predecessors, and the specific regulation mechanism needs further study. Recent studies have found that sly-miR166 and SlyHB modules are susceptible factors of ToLCNDV (New Delhi Tomato Leaf Curl Virus) in tomatoes, Moreover, sly-miR166 and SlyHB were negatively regulated. Therefore, by regulating the expression of sly-miR166, SlyHB can be regulated, thereby regulating the pathogenesis of ToLCNDV. Studies have found that tomato plants carrying the resistant alleles of Slhb15a and miRNA166 develop into normal ovules, and fruit setting can be promoted at extreme temperatures by mutual regulation of Slhb15a and miRNA166. We found that stu-miR166c-5p_L-3 was down-regulated in leaves and roots at seedling stage and up-regulated in leaves and roots at budding stage in Yanshu4 under two N stresses, and up-regulated in roots at budding stage and down-regulated in leaves at budding stage in Atlantic. The specific regulatory mechanism needs further research to fully exert its role in plant biotic and abiotic stress.