Role of bZIP Transcription Factors in Plant Salt Stress.

Soil salinity has become an increasingly serious problem worldwide, greatly limiting crop development and yield, and posing a major challenge to plant breeding. Basic leucine zipper (bZIP) transcription factors are the most widely distributed and conserved transcription factors and are the main regulators controlling various plant response processes against external stimuli. The bZIP protein contains two domains: a highly conserved, DNA-binding alkaline region, and a diverse leucine zipper, which is one of the largest transcription factor families in plants. Plant bZIP is involved in many biological processes, such as flower development, seed maturation, dormancy, and senescence, and plays an important role in abiotic stresses such as salt damage, drought, cold damage, osmotic stress, mechanical damage, and ABA signal response. In addition, bZIP is involved in the regulation of plant response to biological stresses such as insect pests and pathogen infection through salicylic acid, jasmonic acid, and ABA signal transduction pathways. This review summarizes and discusses the structural characteristics and functional characterization of the bZIP transcription factor group, the bZIP transcription factor complex and its molecular regulation mechanisms related to salt stress resistance, and the regulation of transcription factors in plant salt stress resistance. This review provides a theoretical basis and research ideas for further exploration of the salt stress-related functions of bZIP transcription factors. It also provides a theoretical basis for crop genetic improvement and green production in agriculture.

Genome-wide characterization and expression analysis of the growth-regulating factor family in Saccharum.

BACKGROUND: Growth regulating factors (GRFs) are transcription factors that regulate diverse biological and physiological processes in plants, including growth, development, and abiotic stress. Although GRF family genes have been studied in a variety of plant species, knowledge about the identification and expression patterns of GRFs in sugarcane (Saccharum spp.) is still lacking. RESULTS: In the present study, a comprehensive analysis was conducted in the genome of wild sugarcane (Saccharum spontaneum) and 10 SsGRF genes were identified and characterized. The phylogenetic relationship, gene structure, and expression profiling of these genes were analyzed entirely under both regular growth and low-nitrogen stress conditions. Phylogenetic analysis suggested that the 10 SsGRF members were categorized into six clusters. Gene structure analysis indicated that the SsGRF members in the same group were greatly conserved. Expression profiling demonstrated that most SsGRF genes were extremely expressed in immature tissues, implying their critical roles in sugarcane growth and development. Expression analysis based on transcriptome data and real-time quantitative PCR verification revealed that GRF1 and GRF3 were distinctly differentially expressed in response to low-nitrogen stress, which meant that they were additional participated in sugarcane stress tolerance. CONCLUSION: Our study provides a scientific basis for the potential functional prediction of SsGRF and will be further scrutinized by examining their regulatory network in sugarcane development and abiotic stress response, and ultimately facilitating their application in cultivated sugarcane breeding.

Corrigendum: Positive effects of Cordyceps cateniannulata colonization in tobacco: growth promotion and resistance to abiotic stress.

[This corrects the article DOI: 10.3389/fmicb.2023.1131184.].

The role of phytomelatonin receptor 1-mediated signaling in plant growth and stress response.

Phytomelatonin is a pleiotropic signaling molecule that regulates plant growth, development, and stress response. In plant cells, phytomelatonin is synthesized from tryptophan via several consecutive steps that are catalyzed by tryptophan decarboxylase (TDC), tryptamine 5-hydroxylase (T5H), serotonin N-acyltransferase (SNAT), and N-acetylserotonin methyltransferase (ASMT) and/or caffeic acid-3-O-methyltransferase (COMT). Recently, the identification of the phytomelatonin receptor PMTR1 in Arabidopsis has been considered a turning point in plant research, with the function and signal of phytomelatonin emerging as a receptor-based regulatory strategy. In addition, PMTR1 homologs have been identified in several plant species and have been found to regulate seed germination and seedling growth, stomatal closure, leaf senescence, and several stress responses. In this article, we review the recent evidence in our understanding of the PMTR1-mediated regulatory pathways in phytomelatonin signaling under environmental stimuli. Based on structural comparison of the melatonin receptor 1 (MT1) in human and PMTR1 homologs, we propose that the similarity in the three-dimensional structure of the melatonin receptors probably represents a convergent evolution of melatonin recognition in different species.

Positive effects of Cordyceps cateniannulata colonization in tobacco: Growth promotion and resistance to abiotic stress.

Background: Entomopathogenic fungi can live in insects to cause disease and death and are the largest group of entomopathogenic microorganisms. Therefore, these fungi are best known for their microbial control potential. Importantly, they also have other beneficial effects, including promoting plant growth and development by colonizing plant. Here, the study sought to identify specific strains of the entomopathogenic fungus, Cordyceps cateniannulata that would form endophytic associations with tobacco, thus benefiting plant growth and resistance to abiotic stresses, thereby highlighting the application of entomopathogenic fungi in tobacco. Methods: The C. cateniannulata-tobacco symbiont was constructed by root irrigation. The effects of C. cateniannulata on tobacco growth were evaluated by measuring the maximum leaf length, maximum leaf width, number of leaves, plant height, stem thickness, stem circumference, dry and fresh shoot weight 7, 14, 21, and 28 days after colonization. The peroxidase, catalase, superoxide dismutase, and malondialdehyde were measured to observe the impact of C. cateniannulata on tobacco defense enzyme activity. Finally, high-throughput sequencing was used to access microbial communities in the rhizosphere, with data subsequently linked to growth indicators. Results: After tobacco was inoculated with C. cateniannulata X8, which significantly promoted growth and related enzyme activity, malondialdehyde was decreased. The most significant impact was on peroxidase, with its activity being upregulated by 98.20, 154.42, 180.65, and 170.38% in the four time periods, respectively. The high throughput sequencing results indicated that C. cateniannulata had changed the rhizosphere microbial relative abundances, such as increasing Acidobacteria and Ascomycetes, and decreasing Actinomycetes and Basidiomycetes. The redundancy analysis showed that C. cateniannulata significantly boosted tobacco growth by reducing the abundance of specific dominant genera such as Stachybotrys, Cephalotrichum, Streptomyces, Isoptericola, and Microbacterium. Conclusion: Specific strains of C. cateniannulata can be introduced into host plants as endophytes, resulting in promotion of host plant growth and increased resistance to abiotic stress and microbial pathogens. The study provides a foundation for future studies of C. cateniannulata as an ecological agent.

Roles of microRNAs in abiotic stress response and characteristics regulation of plant.

MicroRNAs (miRNAs) are a class of non-coding endogenous small RNAs (long 20-24 nucleotides) that negatively regulate eukaryotes gene expression at post-transcriptional level via cleavage or/and translational inhibition of targeting mRNA. Based on the diverse roles of miRNA in regulating eukaryotes gene expression, research on the identification of miRNA target genes has been carried out, and a growing body of research has demonstrated that miRNAs act on target genes and are involved in various biological functions of plants. It has an important influence on plant growth and development, morphogenesis, and stress response. Recent case studies indicate that miRNA-mediated regulation pattern may improve agronomic properties and confer abiotic stress resistance of plants, so as to ensure sustainable agricultural production. In this regard, we focus on the recent updates on miRNAs and their targets involved in responding to abiotic stress including low temperature, high temperature, drought, soil salinity, and heavy metals, as well as plant-growing development. In particular, this review highlights the diverse functions of miRNAs on achieving the desirable agronomic traits in important crops. Herein, the main research strategies of miRNAs involved in abiotic stress resistance and crop traits improvement were summarized. Furthermore, the miRNA-related challenges and future perspectives of plants have been discussed. miRNA-based research lays the foundation for exploring miRNA regulatory mechanism, which aims to provide insights into a potential form of crop improvement and stress resistance breeding.

Genome-wide analysis of growth-regulating factors (GRFs) in Triticum aestivum.

The Growth-Regulating Factor (GRF) family encodes a type of plant-specific transcription factor (TF). GRF members play vital roles in plant development and stress response. Although GRF family genes have been investigated in a variety of plants, they remain largely unstudied in bread wheat (Triticum aestivum L.). The present study was conducted to comprehensively identify and characterize the T. aestivum GRF (TaGRF) gene family members. We identified 30 TaGRF genes, which were divided into four groups based on phylogenetic relationship. TaGRF members within the same subgroup shared similar motif composition and gene structure. Synteny analysis suggested that duplication was the dominant reason for family member expansion. Expression pattern profiling showed that most TaGRF genes were highly expressed in growing tissues, including shoot tip meristems, stigmas and ovaries, suggesting their key roles in wheat growth and development. Further qRT-PCR analysis revealed that all 14 tested TaGRFs were significantly differentially expressed in responding to drought or salt stresses, implying their additional involvement in stress tolerance of wheat. Our research lays a foundation for functional determination of TaGRFs, and will help to promote further scrutiny of their regulatory network in wheat development and stress response.

Effects of probiotics on feeding intolerance and early growth and development of preterm and very low birth weight infants / 中华健康管理学杂志

Objective:To explore the effects of probiotics on feeding intolerance and early growth and development of preterm and very low birth weight infants (VLBWI).Methods:A total of 446 patients with VLBWI were enrolled in Henan Children′s Hospital from March 20, 2019 to March 20, 2022. They were divided into breast milk group (119 cases), breast milk+probiotic group (108 cases), formula group (115 cases) and formula+probiotic group (104 cases) according to the feeding mode and whether they received early probiotic supplement or not. The feeding programs of each group were carried out according to the “2013 Clinical Application Guide of nutritional support for newborn infants” and “the feeding guidelines for VLBWI”. On this basis, the probiotic supplement group was treated with Clostridium butyricum powder at a dose of 0.25 g/twice a day for 2 weeks, nasal feeding or bottle administration. The incidence of feeding intolerance, the time of recovery of birth weight, the time of reaching total gastrointestinal feeding, and the time of hospitalization in each group were observed, and the average increment of body mass, head circumference and body length in each group at 28 days after birth were compared.Results:In breast milk group, the incidence of feeding intolerance, total gastrointestinal feeding time, and hospital stay were significantly lower than those in the formula group [40.3% vs 47.8%, (13.2±2.4) vs (14.9±1.9) d, (26.5±7.5) vs (29.8±9.6) d], besides, the average increments of early growth and developmental indexes such as body mass, head circumference, and body length at 28 days of birth were significantly lower than those in the formula group [(15.4±2.7) vs (17.7±3.7) g/d, (5.8±1.0) vs (6.2±1.0) mm/week, (6.8±0.7) vs (7.3±0.8) mm/week], however, the recovery time of birth weight in the breast milk group was significantly higher than that in the formula group [(6.2±1.2) vs (5.3±1.4) d] (all P<0.05). The incidence of feeding intolerance, the recovery time of birth weight, the total gastrointestinal feeding time and the hospital stay in the breast milk+probiotics group were significantly lower than those in the breast milk group [34.3% vs 40.3%, (5.4±1.2) vs (6.2±1.2) d, (10.4±1.9) vs (13.2±2.4) d, (22.9±5.6) vs (26.5±7.5) d], besides, the average increments of body mass, head circumference and body length at 28 days of birth was significantly higher than that in the breast milk group [(17.2±3.5) vs (15.4±2.7) g/d, (6.2±1.0) vs (5.8±1.0) mm/week, (7.2±0.8) vs (6.8±0.7) mm/week] (all P<0.05). The incidence of feeding intolerance, total gastrointestinal feeding time and hospital stay in breast milk+probiotics group were significantly lower than those in formula+probiotics group [34.3% vs 47.1%, (10.4±1.9) vs (15.3±2.0) d, (22.9±5.6) vs (30.4±8.2) d] (all P<0.05), besides, there was no significant difference in the average increments of early growth and developmental indexes between the breast milk+probiotics group and the formula+probiotics group (all P>0.05). There were no significant difference in the above indexes between the formula+probiotics group and the formula group (all P>0.05). Conclusion:Probiotics can improve the clinical outcome of feeding intolerance and promote early growth and development of breast feeding VLBWI.