A homologue of flowering locus T gene, designated StFT, was isolated from Solanum tuberosum by reverse transcriptasepolymerase chain reaction （accession no. GU223211）. The DNA sequence of StFT was 1 626 bp long and ...A homologue of flowering locus T gene, designated StFT, was isolated from Solanum tuberosum by reverse transcriptasepolymerase chain reaction （accession no. GU223211）. The DNA sequence of StFT was 1 626 bp long and contained four exons and three introns. The open reading frame of the gene was 522 bp long and encoded a putative protein of 173 amino acids with a molecular weight of 19.75 kD and a theoretical pI of 7.76. StFT protein had a conserved PBP domain and a higher degree of identity with FT homologous members from other species. Analysis on the mRNA levels of StFT showed that it was highly expressed in leaves, apical buds, flowers, and swelling stolons. Further analysis indicated that its expression was regulated by CONSTANS gene in StCOL-antisense transgenic potato plants.展开更多
Aquaporin （AQP） belongs to a highly conserved group of membrane proteins considered as major intrinsic proteins, which facilitate water transport across biological membranes. The discovery of AQPs in plants has resu...Aquaporin （AQP） belongs to a highly conserved group of membrane proteins considered as major intrinsic proteins, which facilitate water transport across biological membranes. The discovery of AQPs in plants has resulted in a paradigm shift in the understanding of plant-water relations, however, the potential relationship between the role of aquaporins in regulating plant water balance and drought tolerance still remains elusive. In this study, the gene encoding potato AQP cDNA, StPIP1 （GenBank accession no. DQ999080）, was cloned from the leaf of potato cultivar Gannongshu 2 by reverse transcription-PCR （RT-PCR）. Sequence alignment was made by BLASTn in GenBank, the phylogenetic analysis was conducted using PHYLIPWY, the 3D structure was predicted in Swiss-Model server. Subcellular localization of StPIP1 was performed by constructing CaMV35S-StPIP1-GFP and rd29A-StPIP1-GFP fusion proteins and transient expression in onion epidermis. To understand StPIP1 physiological functions in potato under various stress conditions, the StPIP1 gene in a reverse orientation was transformed into tobacco driven by the Cauliflower mosaic virus （CMV） 35S promoter. The expression levels of transgenic and wild-type plants were assessed under various abiotic stress conditions using semi-quantitative RT-PCR, and the morphological and physiological responses of transgenic plants to different stress conditions were investigated. The expression of StPIP1 mRNA decreased in transgenic plants under non-stress and stress conditions, however, the reduction was more severer under drought stress. In both non-stress and stress conditions, StPIP1 was expressed predominantly in root. The morphological and physiological investigation showed no significant differences in growth rate, germination rate, and root fresh weight （FW） between transgenic and wild-type plants when grown under favorable conditions. In contrast, under drought stress, the reduction in StPIPI expression leads to a delay in seed germination and seedling growth, accelerated seedling wilt, and leaf morphological abnormity. Under ＂enough＂ water conditions （i.e., water culture）, the aerial parts of anti-sense plants showed no differences. However, for the aerial parts to accumulate the same amount of biomass, transgenic plants needed about 3 times more abundant root system to transport water for plant growth than wild-type plants. Morphological investigation showed that the reduction in StPIP1 expression increased the root system in transgenic plants under drought stress. As a result, the increase of root mass might compensate the reduced cellular water permeability in order to ensure a sufficient water supply for the plant. Results demonstrated that StPIP1 plays an important role for water transportation in potato, especially under drought stress conditions. The reduced expression of StPIP1 decreases the cellular water transport and influences the expression of endogenous AQPs genes and thereby, has impacts on seed germination, seedling growth, and stress responses of potato to drought conditions.展开更多
This study is to investigate the role of lipid transfer protein （LTP1） gene of potato （Solanum tuberosum） in bacterial wilt （Ralstonia solanacearum） resistance. A novel cDNA clone encoding nsLTP was isolated fro...This study is to investigate the role of lipid transfer protein （LTP1） gene of potato （Solanum tuberosum） in bacterial wilt （Ralstonia solanacearum） resistance. A novel cDNA clone encoding nsLTP was isolated from cultivated potato （Solanum tuberosum） infected with R. solanacearum by 5＇-rapid amplification of cDNA ends （RACE）. The temporal and spatial expression of StLTPbl was studied during the early stages of potato-R, solanacearum interaction by reverse transcriptase PCR （RT-PCR） and Northern blotting. The sequence analysis of the cloned cDNA, named StLTPbl, showed 691 bp which encoded a type 1 nsLTP of 91 amino acids. Construction of a phylogenic tree showed that StLTPbl is well conserved in the coding region with high identity at the amino acid level with other Solanaceae nsLTPs. The temporal and spatial expression of StLTPbl was studied during the early stages of potato-R, solanacearum interaction. StLTPbl transcription is induced faster and transcripts accumulate to higher concentrations in resistant compared with susceptible genotypes by the pathogen. Dominant differences in the pathogen-induced gene expression pattern between the upper and lower leaves and stems were observed within the same genotypes. In situ hybridization results showed that the StLTPbl mRNA was localized in phloem cells of vascular tissues in potato leaf and stem tissues after pathogen infection. Salicylic acid, methyl jasmonate and abscisic acid could induce StLTPbl gene expression without significant difference between the upper and lower tissues. These abiotic elicitors could produce a long-lastingeffect on the StLTPbl during early stages of potato-R, solanacearum interaction. Differential expression of StLTPbl gene between resistance and susceptible potato genotypes in response to R. solanacearum suggests that this gene plays a key role in plant defense mechanisms.展开更多
The effects of Ce （Ⅳ） on callus growth, anthocyanin content, and expression of anthocyanin biosynthetic genes in callus suspension cultures of Solanum tuberosum cv. Chieftain were studied by the measurement of fres...The effects of Ce （Ⅳ） on callus growth, anthocyanin content, and expression of anthocyanin biosynthetic genes in callus suspension cultures of Solanum tuberosum cv. Chieftain were studied by the measurement of fresh weight, spectrophotometric assays, and semiquantitative RT-PCR. The results indicate that 0.1 mmol·L^- 1 Ce （ Ⅳ ） can promote callus growth, increase the accumulation of anthocyanins, and enhance the expression of five anthocyanin biosynthetic genes （ CHS, F3H, F3＇5＇H, DFR, and 3 GT） most efficiently. At high concentrations of 1 mmol·L^- 1, Ce （Ⅳ） partially inhibits callus growth and at 2 mmol· L^-1 eventually lends to cell death. The results show that Ce（ Ⅳ ） can induce the expression of anthocyanin biosynthetic genes to produce and accumulate anthocyanins and increase the yield of anthocyanins.展开更多
基金supported by grants from the Opening Foundation of the Jiangsu Key Laboratory for Eco-Agricultural Biotechnology Around HongzeLake,Jiangsu Province,China(HZHL0807)the State Key Laboratory of Crop Genetics and Germplasm Enhancement,Ministry of Sciences and Technology,China(ZW2007003)
文摘A homologue of flowering locus T gene, designated StFT, was isolated from Solanum tuberosum by reverse transcriptasepolymerase chain reaction （accession no. GU223211）. The DNA sequence of StFT was 1 626 bp long and contained four exons and three introns. The open reading frame of the gene was 522 bp long and encoded a putative protein of 173 amino acids with a molecular weight of 19.75 kD and a theoretical pI of 7.76. StFT protein had a conserved PBP domain and a higher degree of identity with FT homologous members from other species. Analysis on the mRNA levels of StFT showed that it was highly expressed in leaves, apical buds, flowers, and swelling stolons. Further analysis indicated that its expression was regulated by CONSTANS gene in StCOL-antisense transgenic potato plants.
基金supported by the National 973 Program of China (2006CB708200)Gansu Province Key Technologies R&D Program (2GS054-A41-00501),Chinathe President Youth Fund of Academy of Agri-Sciences Anhui Province, China (200933)
文摘Aquaporin （AQP） belongs to a highly conserved group of membrane proteins considered as major intrinsic proteins, which facilitate water transport across biological membranes. The discovery of AQPs in plants has resulted in a paradigm shift in the understanding of plant-water relations, however, the potential relationship between the role of aquaporins in regulating plant water balance and drought tolerance still remains elusive. In this study, the gene encoding potato AQP cDNA, StPIP1 （GenBank accession no. DQ999080）, was cloned from the leaf of potato cultivar Gannongshu 2 by reverse transcription-PCR （RT-PCR）. Sequence alignment was made by BLASTn in GenBank, the phylogenetic analysis was conducted using PHYLIPWY, the 3D structure was predicted in Swiss-Model server. Subcellular localization of StPIP1 was performed by constructing CaMV35S-StPIP1-GFP and rd29A-StPIP1-GFP fusion proteins and transient expression in onion epidermis. To understand StPIP1 physiological functions in potato under various stress conditions, the StPIP1 gene in a reverse orientation was transformed into tobacco driven by the Cauliflower mosaic virus （CMV） 35S promoter. The expression levels of transgenic and wild-type plants were assessed under various abiotic stress conditions using semi-quantitative RT-PCR, and the morphological and physiological responses of transgenic plants to different stress conditions were investigated. The expression of StPIP1 mRNA decreased in transgenic plants under non-stress and stress conditions, however, the reduction was more severer under drought stress. In both non-stress and stress conditions, StPIP1 was expressed predominantly in root. The morphological and physiological investigation showed no significant differences in growth rate, germination rate, and root fresh weight （FW） between transgenic and wild-type plants when grown under favorable conditions. In contrast, under drought stress, the reduction in StPIPI expression leads to a delay in seed germination and seedling growth, accelerated seedling wilt, and leaf morphological abnormity. Under ＂enough＂ water conditions （i.e., water culture）, the aerial parts of anti-sense plants showed no differences. However, for the aerial parts to accumulate the same amount of biomass, transgenic plants needed about 3 times more abundant root system to transport water for plant growth than wild-type plants. Morphological investigation showed that the reduction in StPIP1 expression increased the root system in transgenic plants under drought stress. As a result, the increase of root mass might compensate the reduced cellular water permeability in order to ensure a sufficient water supply for the plant. Results demonstrated that StPIP1 plays an important role for water transportation in potato, especially under drought stress conditions. The reduced expression of StPIP1 decreases the cellular water transport and influences the expression of endogenous AQPs genes and thereby, has impacts on seed germination, seedling growth, and stress responses of potato to drought conditions.
基金grateful to Ren Caihong(College of Life Science,Shanxi Normal University of China)for technical assistance.This work was supported by National 863 Program(2003AA207130)Natural Science Foundation of Shanxi Province of China(20051042).
文摘This study is to investigate the role of lipid transfer protein （LTP1） gene of potato （Solanum tuberosum） in bacterial wilt （Ralstonia solanacearum） resistance. A novel cDNA clone encoding nsLTP was isolated from cultivated potato （Solanum tuberosum） infected with R. solanacearum by 5＇-rapid amplification of cDNA ends （RACE）. The temporal and spatial expression of StLTPbl was studied during the early stages of potato-R, solanacearum interaction by reverse transcriptase PCR （RT-PCR） and Northern blotting. The sequence analysis of the cloned cDNA, named StLTPbl, showed 691 bp which encoded a type 1 nsLTP of 91 amino acids. Construction of a phylogenic tree showed that StLTPbl is well conserved in the coding region with high identity at the amino acid level with other Solanaceae nsLTPs. The temporal and spatial expression of StLTPbl was studied during the early stages of potato-R, solanacearum interaction. StLTPbl transcription is induced faster and transcripts accumulate to higher concentrations in resistant compared with susceptible genotypes by the pathogen. Dominant differences in the pathogen-induced gene expression pattern between the upper and lower leaves and stems were observed within the same genotypes. In situ hybridization results showed that the StLTPbl mRNA was localized in phloem cells of vascular tissues in potato leaf and stem tissues after pathogen infection. Salicylic acid, methyl jasmonate and abscisic acid could induce StLTPbl gene expression without significant difference between the upper and lower tissues. These abiotic elicitors could produce a long-lastingeffect on the StLTPbl during early stages of potato-R, solanacearum interaction. Differential expression of StLTPbl gene between resistance and susceptible potato genotypes in response to R. solanacearum suggests that this gene plays a key role in plant defense mechanisms.
基金Project Supported bythe International Cooperation Research of Jiangsu Province (BZ2003041)
文摘The effects of Ce （Ⅳ） on callus growth, anthocyanin content, and expression of anthocyanin biosynthetic genes in callus suspension cultures of Solanum tuberosum cv. Chieftain were studied by the measurement of fresh weight, spectrophotometric assays, and semiquantitative RT-PCR. The results indicate that 0.1 mmol·L^- 1 Ce （ Ⅳ ） can promote callus growth, increase the accumulation of anthocyanins, and enhance the expression of five anthocyanin biosynthetic genes （ CHS, F3H, F3＇5＇H, DFR, and 3 GT） most efficiently. At high concentrations of 1 mmol·L^- 1, Ce （Ⅳ） partially inhibits callus growth and at 2 mmol· L^-1 eventually lends to cell death. The results show that Ce（ Ⅳ ） can induce the expression of anthocyanin biosynthetic genes to produce and accumulate anthocyanins and increase the yield of anthocyanins.
