Gene expression analysis of potato drought-responsive genes under drought stress in potato (Solanum tuberosum L.) cultivars

The potato (Solanum tuberosum L.), an important field crop consumed extensively worldwide, is adversely affected by abiotic stress factors especially drought. Therefore, it is vital to understand the genetic mechanism under drought stress to decrease loose of yield and quality . This trial aimed to screen drought-responsive gene expressions of potato and determine the drought-tolerant potato cultivar. The trial pattern is a completely randomized block design (CRBD) with four replications under greenhouse conditions. Four cultivars (Brooke, Orwell, Vr808, Shc909) were irrigated with four different water regimes (control and three stress conditions), and the gene expression levels of 10 potato genes were investigated. The stress treatments as follows: Control = 100% field capacity; slight drought = 75% field capacity; moderate drought = 50% field capacity, and severe drought 25% field capacity. To understand the gene expression under drought stress in potato genotypes, RT-qPCR analysis was performed and results showed that the genes most associated with drought tolerance were the StRD22 gene, MYB domain transcription factor, StERD7, Sucrose Synthase (SuSy), ABC Transporter, and StDHN1. The StHSP100 gene had the lowest genetic expression in all cultivars. Among the cultivars, the Orwell exhibited the highest expression of the StRD22 gene under drought stress. Overall, the cultivar with the highest gene expression was the Vr808, closely followed by the Brooke cultivar. As a result, it was determined that potato cultivars Orwell, Vr808, and Brooke could be used as parents in breeding programs to develop drought tolerant potato cultivars.

Identification and functional analysis of non-coding regulatory small RNA FenSr3 in Bacillus amyloliquefaciens LPB-18

Bacillus amyloliquefaciens is an interesting microbe in the food processing and manufacturing industries. Non-coding small RNAs (sRNAs) have been shown to play a crucial role in the physiology and metabolism of bacteria by post-transcriptionally regulating gene expression. This study investigated the function of novel sRNA FenSr3 by constructing fenSr3 deficient strain and complementary strains in B. amyloliquefaciens LPB-18 , which were named LPN-18N and LPB-18P, respectively. The result showed significant differences in fengycin yield between strain LPB -18N and LPB-18P. The production of fengycin was significantly enhanced in B. amyloliquefaciens LPB-18N, compared with that of the strain LPB-18 from 190.908 mg/L to 327.598 mg/L. Moreover, the production of fengycin decreased from 190.464 mg/L to 38.6 mg/L in B . amyloliquefaciens LPB-18P. A comparative transcriptome sequencing was carried out to better understand the complex regulatory mechanism. Transcription analysis revealed that 1037 genes were differentially expressed between B. amyloliquefaciens LPB-18 and B. amyloliquefaciens LPB-18N, including the key regulatory genes in fatty acid, amino acid biosynthesis, and central carbon metabolism, which could provide sufficient quantities of building precursors for fengycin biosynthesis. The biofilm formation and sporulation was also enhanced in the strain LPB-18N, which indicates that FenSr3 could play a vital role in stress resistance and promotes survival in B. amyloliquefaciens. Some sRNAs involved in stress response have been identified in the literature, but their regulatory roles in fengycin production remain unclear. The study will contribute a novel perspective to the regulation mechanism of biosynthesis and the optimization of key metabolites of B. amyloliquefaciens.

Physiological changes and transcript identification in Coreopsis tinctoria Nutt. in early stages of salt stress

Coreopsis tinctoria Nutt. (C. tinctoria) is a special tea ingredient that adapts to certain salt stresses and shares the functions of chrysanthemum. With annual expansion of the cultivation area of C. tinctoria in Xinjiang (China), soil salinity may become a constraint for chrysanthemum cultivation. To investigate the response of C. tinctoria to salt stress, physiological and transcriptional changes in C. tinctoria in the early stages of low (50 mM NaCl) and high (200 mM NaCl) salt stress were analyzed and identified. The results showed that the contents of osmotic regulators (free proline, soluble sugar, and soluble protein) and antioxidant enzymes (catalase and peroxidase) under salt stress increased to various extents compared with those of the control (CK) within 72 h, and the increase was higher under 200 mM NaCl treatments. De novo RNA-seq was used to analyze changes in the transcripts under 50 and 200 mM NaCl treatments for up to 48 h. In total, 8,584, 3,760, 7,833, 19,341, 13,233, and 9,224 differentially expressed genes (DEGs) were detected under 12 h, 24 h, and 48 h for 50 and 200 mM NaCl treatments, respectively. Weighted correlation network analysis (WGCNA) was used to analyze the correlations between all DEGs and physiological indexes. We found that the coexpression modules blue2 and Lightskyblue4 highly correlated with osmotic regulators and CAT and identified 20 and 30 hub genes, respectively. The results provide useful data for the further study of salt tolerance in C. tinctoria.

Transcriptomics analysis reveals the effect of Broussonetia papyrifera L. fermented feed on meat quality traits in fattening lamb

To date, utilization of feed grains is increasing, which competes for human food. It is imperative to develop and utilize unconventional feed materials. Broussonetia papyrifera L. (B. papyrifera) is a good feeding material with high crude protein, crude fat, and low crude fiber, which is widely distributed in China. In this study, 12 Dorper ♂×Hu ♀  crossbred weaned male lambs were seleted into four groups based on the feed that ratio of the B. papyrifera fermented feed in the total mixed diet (0%, 6%, 18%, and 100%), to character the lambs' longissimus dorsi (LD) fatty acids, morphology and transcriptome. Results showed that the muscle fiber's diameter and area were the smallest in the 100% group. The highest content of beneficial fatty acids and the lowest content of harmful fatty acids in group 18%. RNA-seq identified 443 differentially expressed genes (DEGs) in the LD of lambs from 4 groups. Among these genes, 169 (38.1%) were up-regulated and 274 (61.9%) were down-regulated. The DEGs were mostly enriched in in fatty acid metabolism, arginine and proline metabolism, and PPAR signaling pathways. Our results provide knowledge to understand effect of different ratios of B. papyrifera fermented feed on sheep meat quality traits, also a basis for understanding of the molecular regulation mechanism of B. papyrifera fermented feed affecting on sheep meat quality.