Genome-wide identification of the C2H2 zinc finger gene family and expression analysis under salt stress in sweetpotato.

Introduction: The higher plant transcription factor C2H2 zinc finger protein (C2H2-ZFP) is essential for plant growth, development, and stress response. There are limited studies on C2H2-ZFP genes in sweetpotato, despite a substantial number of C2H2-ZFP genes having been systematically found in plants. Methods: In this work, 178 C2H2-ZFP genes were found in sweetpotato, distributed randomly on 15 chromosomes, and given new names according to where they were located. These members of the zinc finger gene family are separated into six branches, as shown by the phylogenetic tree. 24 tandem repeats of IbZFP genes and 46 fragment repeats were identified, and a homology study revealed that IbZFP genes linked more regions with wild relative species of sweetpotato as well as rhizome plants like potato and cassava. And we analyzed the expression patterns of IbZFP genes during the early development of sweetpotato storage roots (SRs) and salt stress using transcriptome data, and identified 44 IbZFP genes that exhibited differences in expression levels during the early expansion of sweetpotato SRs in different varieties, and 92 IbZFP genes that exhibited differences in expression levels under salt stress in salt tolerant and salt sensitive sweetpotato varieties. Additionally, we cloned six IbZFP genes in sweetpotato and analyzed their expression patterns in different tissues, their expression patterns under abiotic stress and hormone treatment, and subcellular localization. Results and discussion: The results showed that the IbZFP genes had tissue specificity in sweetpotato and were induced to varying degrees by drought and salt stress. ABA and GA3 treatments also affected the expression of the IbZFP genes. We selected IbZFP105, which showed significant differences in expression levels under salt stress and ABA treatment, to be heterologously expressed in Arabidopsis thaliana. We found that IbZFP105 OE lines exhibited higher tolerance to salt stress and ABA stress. This indicates that IbZFP105 can enhance the salt tolerance of plants. These results systematically identified the evolution and expression patterns of members of the C2H2-ZFP gene family in sweetpotato, providing a theoretical basis for studying the role of IbZFP genes in the development of sweetpotato SRs and in resistance to stress.

Overexpression of 9-cis-Epoxycarotenoid Dioxygenase Gene, IbNCED1, Negatively Regulates Plant Height in Transgenic Sweet Potato.

Plant height is one of the key agronomic traits for improving the yield of sweet potato. Phytohormones, especially gibberellins (GAs), are crucial to regulate plant height. The enzyme 9-cis-epoxycarotenoid dioxygenase (NCED) is the key enzyme for abscisic acid (ABA) biosynthesis signalling in higher plants. However, its role in regulating plant height has not been reported to date. Here, we cloned a new NCED gene, IbNCED1, from the sweet potato cultivar Jishu26. This gene encoded the 587-amino acid polypeptide containing an NCED superfamily domain. The expression level of IbNCED1 was highest in the stem and the old tissues in the in vitro-grown and field-grown Jishu26, respectively. The expression of IbNCED1 was induced by ABA and GA3. Overexpression of IbNCED1 promoted the accumulation of ABA and inhibited the content of active GA3 and plant height and affected the expression levels of genes involved in the GA metabolic pathway. Exogenous application of GA3 could rescue the dwarf phenotype. In conclusion, we suggest that IbNCED1 regulates plant height and development by controlling the ABA and GA signalling pathways in transgenic sweet potato.

Clinical Evaluation of Comfort Nursing in Gynecological Patients Undergoing Laparoscopic Surgery.

Background: Laparoscopic surgery is a standard procedure for gynecological patients but can be associated with discomfort and anxiety. Comfort nursing interventions have been proposed as a potential approach to improve the well-being and outcomes of patients undergoing such surgeries. Objective: This study aimed to assess the impact of comfort nursing on patient comfort, anxiety, and depression levels during the postoperative period of laparoscopic surgery. Methods: A total of 90 gynecological patients with ovarian cysts were randomly assigned to either the control group (n = 45), receiving conventional nursing, or the experimental group (n = 45), receiving comfort nursing. The General Comfort Questionnaire (GCQ) and the Hospital Anxiety and Depression (HAD) scale were utilized to measure patient comfort and psychological well-being. Data analysis was performed using t tests, Fisher's exact test, and chi-square tests. Results: The results demonstrated that the experimental group receiving comfort nursing had significantly higher scores in the environment domain and total GCQ score than the control group (P < .05). However, there were no statistically significant differences between the two groups in the physiology, psychology, and society domains of the GCQ. Moreover, the experimental group had better HAD scores compared to the control group (P < .05). Conclusions: This study provides evidence that comfort nursing is an effective approach to improving patient comfort and reducing anxiety in gynecological patients undergoing laparoscopic surgery for ovarian cysts. Implementing comfort nursing interventions can enhance the overall care experience for these patients and potentially contribute to better surgical outcomes.

Nitrogen utilization characteristics and early storage root development in nitrogen-tolerant and nitrogen-susceptible sweet potato.

In recent years, sweet potato has been cultivated not only in marginal lands but also in fertile plains in northern China. The fertile nitrogen (N)-rich soil may inhibit storage root formation. Cultivars with different N tolerances and split application of reduced N rates should be considered. To investigate the effects of N on the N utilization, root differentiation, and storage root formation of cultivars with different N tolerances, the cultivars Jishu26 (J26) and Xushu32 (X32) were treated with three N levels supplied by urea: 0 (N0), 200 (N1) and 400 mg kg-1 (N2). With increasing N rates, "X32" absorbed less N in plants and distributed more N to developing storage roots than "J26." The storage root development of "J26" was sensitive to both N1 and N2, while that of "X32" was only sensitive to N2. High N nutrition upregulated the expression of certain genes during storage root formation, such as PAL, CHI, F3H, C4 H, 4CL, CAD, α-amylase, and ß-amylase. Under N1 and N2, "X32" led to an increased sugar supply in sink organs and downregulated the expression of genes related to lignin and flavonoid synthesis, which promoted the C flux toward starch metabolism, thus reducing lignification and promoting starch accumulation during storage root formation. These results provide evidence for the effects of N on the C distribution in different metabolic pathways by regulating the expression of related key genes. N-tolerant cultivars are suitable in fertile plain areas because of the earlier formation of storage roots under high N conditions.

Genome-wide in silico identification and expression analysis of beta-galactosidase family members in sweetpotato [Ipomoea batatas (L.) Lam].

BACKGROUND: Sweetpotato (Ipomoea batatas (L.) Lam.) serves as an important food source for human beings. ß-galactosidase (bgal) is a glycosyl hydrolase involved in cell wall modification, which plays essential roles in plant development and environmental stress adaptation. However, the function of bgal genes in sweetpotato remains unclear. RESULTS: In this study, 17 ß-galactosidase genes (Ibbgal) were identified in sweetpotato, which were classified into seven subfamilies using interspecific phylogenetic and comparative analysis. The promoter regions of Ibbgals harbored several stress, hormone and light responsive cis-acting elements. Quantitative real-time PCR results displayed that Ibbgal genes had the distinct expression patterns across different tissues and varieties. Moreover, the expression profiles under various hormonal treatments, abiotic and biotic stresses were highly divergent in leaves and root. CONCLUSIONS: Taken together, these findings suggested that Ibbgals might play an important role in plant development and stress responses, which provided evidences for further study of bgal function and sweetpotato breeding.

Comparative analysis of full-length transcriptomes based on hybrid population reveals regulatory mechanisms of anthocyanin biosynthesis in sweet potato (Ipomoea batatas (L.) Lam).

BACKGROUND: Sweet potato (Ipomoea batatas (L.) Lam.) is a highly heterozygous autohexaploid crop with high yield and high anthocyanin content. Purple sweet potato is the main source of anthocyanins, and the mechanism of anthocyanin biosynthesis in storage roots has not been fully revealed. RESULTS: In order to reveal the mechanism of anthocyanin biosynthesis and identify new homologous genes involved in anthocyanin biosynthesis in the storage roots of sweet potato, we used Ningzishu 1 and Jizishu 2 as parents to construct a F1 hybrid population. Seven anthocyanin-containing lines and three anthocyanin-free lines were selected for full-length and second-generation transcriptome analyses. A total of 598,375 circular consensus sequencing reads were identified from full-length transcriptome sequencing. After analysis and correction of second-generation transcriptome data, 41,356 transcripts and 18,176 unigenes were obtained. Through a comparative analysis between anthocyanin-containing and anthocyanin-free groups 2329 unigenes were found to be significantly differentially expressed, of which 1235 were significantly up-regulated and 1094 were significantly down-regulated. GO enrichment analysis showed that the differentially expressed unigenes were significantly enriched in molecular function and biological process. KEGG enrichment analysis showed that the up-regulated unigenes were significantly enriched in the flavonoid biosynthesis and phenylpropanoid biosynthesis pathways, and the down-regulated unigenes were significantly enriched in the plant hormone signal transduction pathway. Weighted gene co-expression network analysis of differentially expressed unigenes revealed that anthocyanin biosynthesis genes were co-expressed with transcription factors such as MYB, bHLH and WRKY at the transcription level. CONCLUSIONS: Our study will shed light on the regulatory mechanism of anthocyanin biosynthesis in sweet potato storage roots at the transcriptome level.

Differences between nitrogen-tolerant and nitrogen-susceptible sweetpotato cultivars in photosynthate distribution and transport under different nitrogen conditions.

To characterize the differences in photosynthate distribution and transport between nitrogen(N)-tolerant and N-susceptible sweetpotato cultivars under different N conditions, three N levels, including 0 (N0), 120 (N120), and 240 kg ha-1 (N240), were used in field experiments with the Jishu26 (J26) and Xushu32 (X32) cultivars in 2015 and 2016. The results from both years revealed that high N application reduced the tuberous root yield, the tuber/vine rate of carbon-13 (13C), and top-to-base (three equal segments of stem divided from the fifth opened leaf of the shoot tip to the main stem, defined as the top, middle, and base parts, respectively) gradients such as sucrose, ammonia N and potassium along the stem. 'J26' showed a higher yield than 'X32' under N0 but lower yield than 'X32' under N120 and N240. It also exhibited a higher 13C distribution to tuberous roots compared with that of 'X32' under N0, and the opposite trend was observed under N120 and N240. Under N0, 'J26' showed a steep top-to-base amino acid gradient and a significantly lower top-to-base sucrose increase along the stem in the late growth stage. Under N120 and N240, 'X32' exhibited a greater top-to-base decrease in the ammonia N along the stem during the main growth stages, a steep top-to-base sucrose gradient along the stem in the early growth stage, and a lower top-to-base sucrose increase along the stem in the middle and late growth stages. The formation of a reasonable photosynthate distribution structure attributed to high yield was related to a desirable sucrose, ammonia N or K+ gradient downward along the stem. These results might help provide farmers with sweetpotato cultivars using less or no N fertilizer in soils of different fertility and enhance the knowledge of yield-related physiology.

Evolution Analysis of Simple Sequence Repeats in Plant Genome.

Simple sequence repeats (SSRs) are widespread units on genome sequences, and play many important roles in plants. In order to reveal the evolution of plant genomes, we investigated the evolutionary regularities of SSRs during the evolution of plant species and the plant kingdom by analysis of twelve sequenced plant genome sequences. First, in the twelve studied plant genomes, the main SSRs were those which contain repeats of 1-3 nucleotides combination. Second, in mononucleotide SSRs, the A/T percentage gradually increased along with the evolution of plants (except for P. patens). With the increase of SSRs repeat number the percentage of A/T in C. reinhardtii had no significant change, while the percentage of A/T in terrestrial plants species gradually declined. Third, in dinucleotide SSRs, the percentage of AT/TA increased along with the evolution of plant kingdom and the repeat number increased in terrestrial plants species. This trend was more obvious in dicotyledon than monocotyledon. The percentage of CG/GC showed the opposite pattern to the AT/TA. Forth, in trinucleotide SSRs, the percentages of combinations including two or three A/T were in a rising trend along with the evolution of plant kingdom; meanwhile with the increase of SSRs repeat number in plants species, different species chose different combinations as dominant SSRs. SSRs in C. reinhardtii, P. patens, Z. mays and A. thaliana showed their specific patterns related to evolutionary position or specific changes of genome sequences. The results showed that, SSRs not only had the general pattern in the evolution of plant kingdom, but also were associated with the evolution of the specific genome sequence. The study of the evolutionary regularities of SSRs provided new insights for the analysis of the plant genome evolution.

[Study on early stability by ISSR markers in rice].

In the F2 population crossed from two early stability rice (Oryza sativa L.) with four cultivars, eight uniform strains were recorded. Genetic analysis showed that both uniform strains with uniform agronomic characteristics and segregated strains segregating in Mendelian manner were observed in F2 population of the same combination. Four types of marker-bands were obtained after the F2 uniform strains were marked by 26 ISSR primers:t ype I, maternal marker bands present, and paternal marker bands absent; type II, paternal marker bands present, and maternal marker bands absent; type III, parts of maternal and paternal marker bands present, and the others absent; type IV, new recombined marker bands appeared, and all maternal and paternal marker bands absent. But segregating strains showed heterzygosity marker bands, maternal and paternal marker bands being present. The uniform strains and normal strains in rice might be grouped into two classes on the basis of the 2000 bp marker band amplified by the ISSR marker primers No. 900. This result would provide experimental basis for the study on genetic mechanism of early stability in rice.