Downregulation of SL-ZH13 transcription factor gene expression decreases drought tolerance of tomato

Zinc finger-homeodomain proteins(ZF-HDs) are transcription factors that regulate plant growth,development,and abiotic stress tolerance.The SL-ZH13 gene was found to be significantly upregulated under drought stress treatment in tomato(Solanum lycopersicum) leaves in our previous study.In this study,to further understand the role that the SL-ZH13 gene plays in the response of tomato plants to drought stress,the virus-induced gene silencing(VIGS) method was applied to downregulate SL-ZH13 expression in tomato plants,and these plants were treated with drought stress to analyze the changes in drought tolerance.The SL-ZH13 silencing efficiency was confirmed by quantitative real-time PCR(qRT-PCR) analysis.In SL-ZH13-silenced plants,the stems wilted faster,leaf shrinkage was more severe than in control plants under the same drought stress treatment conditions,and the mean stem bending angle of SL-ZH13-silenced plants was smaller than that of control plants.Physiological analyses showed that the activity of superoxide dismutase(SOD) and peroxidase(POD) and the content of proline(Pro) in SL-ZH13-silenced plants were lower than those in control plants after 1.5 and 3 h of drought stress treatment.The malondialdehyde(MDA) content in SL-ZH13-silenced plants was higher than that in control plants after 1.5 and 3 h of drought stress treatment,and H2O2 and O2^-· accumulated much more in the leaves of SL-ZH13-silenced plants than in the leaves of control plants.These results suggested that silencing the SL-ZH13 gene affected the response of tomato plants to drought stress and decreased the drought tolerance of tomato plants.

Silencing the SLB3 transcription factor gene decreases drought stress tolerance in tomato

BRI1-EMS-SUPPRESSOR 1(BES1)transcription factor is closely associated with the brassinosteroid(BR)signaling pathway and plays an important role in plant growth and development.SLB3 is a member of BES1 transcription factor family and its expression was previously shown to increase significantly in tomato seedlings under drought stress.In the present study,we used virus-induced gene silencing(VIGS)technology to downregulate SLB3 expression to reveal the function of the SLB3 gene under drought stress further.The downregulated expression of SLB3 weakened the drought tolerance of the plants appeared earlier wilting and higher accumulation of H2 O2 and O2^–·,decreased superoxide dismutase(SOD)activity,and increased proline(PRO)and malondialdehyde(MDA)contents and peroxidase(POD)activity.Quantitative real-time PCR(qRT-PCR)analysis of BR-related genes revealed that the expression of SlCPD,SlDWARF and BIN2-related genes was significantly upregulated in SLB3-silenced seedlings under drought stress,but that the expression of TCH4-related genes was downregulated.These results showed that silencing the SLB3 gene reduced the drought resistance of tomato plants and had an impact on the BR signaling transduction which may be probably responsible for the variation in drought resistance of the tomato plants.

Genome-wide identification and expression analysis of GDSL esterase/lipase genes in tomato

The GDSL esterase/lipase family contains many functional genes that perform important biological functions in growth and development, morphogenesis, seed oil synthesis, and defense responses in plants. The expression of GDSL esterase/lipase genes can respond to biotic and abiotic stresses. Although GDSL esterase/lipase family genes have been identified and studied in other plants, they have not been identified and their functions remain unclear in tomato. This study is the first to identify 80 GDSL esterase/lipase family genes in tomato, which were named SlGELP1–80. These genes were mapped to their positions on the chromosomes and their physical and chemical properties, gene structure, phylogenetic relationships, collinear relationships, and cis-acting elements were analyzed. The spatiotemporal expression characteristics of the Sl GELP genes in tomato were diverse. In addition, RNA-seq analysis indicated that the expression patterns of the SlGELP genes in tomato differed before and after inoculation with Stemphylium lycopersici. qRT-PCR was used to analyze the expression of five Sl GELP genes after treatments with S. lycopersici, salicylic acid and jasmonic acid. Finally, this study was the first to identify and analyze GDSL esterase/lipase family genes in tomato via bioinformatics approaches, and these findings provide new insights for improving the study of plant disease resistance.

Bioinformatics and Expression Pattern Analysis of Tomato ns LTP 2-like cDNA full-length Gene Clone

TDF1(transcription-drived fragment) was homologous to the predicted S. lycopersicum nonspecific lipid-transfer protein,nsLTP 2-like(91%), and it was significantly upregulated in response to C. fulvum(cladosporium fulvum) infection in tomato plants.In this experiment, the full-length cDNA of nsLTP 2-like was cloned using RACE technology based on the sequence of TDF1(GenBank: JZ717725). A full-length, 625 bp(GenBank: KU366289), cDNA sequence, which with 98% similarity to nsLTP 2-like gene(GenBank: XM015233692) was obtained. This cDNA contains an ORF(open reading frame) with full-length of 345 bp, coding of 114 amino acids, including 12.3% Ala and Gly. Protein molecular weight was 11.51 ku, the isoelectric point(pI) was 8.99, and average overall hydrophilicity was 0.412, with one phosphorylation sites, belonging to volatile acidic nuclear protein. Secondary structure prediction showed that α-Helix accounts for 30.7%, extension chain for 12.28%, β-corner for 9.65%, and random coil for 47.37%. Through comparative analysis of the homology among species, it was found that the amino acid sequence of tomato nsLTP 2-like protein had a high similarity with other plants, and with a specific conserved sequence which might related features in nsLTP 2-like protein. It also be analyzed the gene expression pattern of tomato in different parts and under different stress conditions.The results showed that nsLTP 2-like gene was up-regulated in varying degrees, under the condition of cold stress, exogenous hormone spraying and cladosporium fulvum infection. Therefore, it was speculated that the gene played a role in response to abiotic and biotic stress in tomato.

Development of Molecular Marker Linked to Cf-10 Gene Using SSR and AFLP Method in Tomato

The leaf mould resistance gene Cf-10 on tomato confered resistant or immune to all prevalent physiological races of Cladosporium fulvum presented in three northeastern provinces of China in inoculation test. In order to better utilize Cf-10 gene in a marker-assisted selection program and to permit the pyramiding of one or several resistance genes in a cultivar, tightly linked SSR and AFLP markers were obtained by the bulked segregant analysis method. One SSR marker and three AFLP markers were identified linked to Cf-10 gene, with the distance of 9.73, 5.8, 8.5, and 10.6 cM, respectively. These markers will facilitate the selection of resistant tomato germplasm containing Cf-10 gene.

急性非静脉曲张性上消化道出血患者RDW、D-D、S100A12与病情和临床结局的关系

目的:探讨急性非静脉曲张性上消化道出血(ANVUGIB)患者红细胞分布宽度(RDW)、D二聚体(D-D)、S100钙结合蛋白12(S100A12)与病情和临床结局的关系。方法:选择2021年7月至2023年8月贵阳市第一人民医院收治的ANVUGIB患者184例作为研究组,同期体检健康者100例作为对照组。根据Rockall危险积分将患者分为低危组(28例)、中危组(60例)、高危组(96例),根据住院期间临床结局将患者分为预后不良组(66例)和预后良好组(118例)。检测RDW、血浆D-D、血清S100A12水平。采用多因素Logistic回归分析ANVUGIB患者临床结局不良的危险因素。结果:研究组RDW、血浆D-D、血清S100A12水平高于对照组(P<0.05)。高危组RDW、血浆D-D、血清S100A12水平显著高于中危组、低危组,中危组RDW、血浆D-D、血清S100A12水平显著高于低危组(P<0.05)。结局不良组患者RDW、血浆D-D、血清S100A12水平高于结局良好组(P<0.05)。多因素Logsitic回归分析显示,Rockall危险积分升高、出血量>1000 m L、RDW升高、血浆D-D升高、血清S100A12升高是ANVUGIB患者临床结局不良的危险因素(P<0.05)。结论:ANVUGIB患者RDW、D-D、S100A12水平与患者病情和临床结局密切相关,RDW升高、血浆D-D升高、血清S100A12升高是ANVUGIB患者临床结局不良的危险因素。