Plant trichomes are special structures that originate from epidermal outgrowths. Trichomes play an important role in plant defense against pests and diseases, and possess economic and medicinal values. Study on molecular mechanism of plant trichomes will contribute to the molecular design breeding and genetic improvement of crops. In recent years, the regulation mechanism of trichome development has been basically clarified in the model plant Arabidopsis thaliana, while great progresses are also found in other plant species. In this review, we focus on the developmental regulation of trichome formation from gene and phytohormones levels in Arabidopsis and cotton (with unicellular trichomes), as well as in tomato and Artemisia annua (with multicellular trichomes). The research progress associated with trichomes is also introduced in other typical monocotyledons and dicotyledons. Finally, the research and application of plant trichomes are prospected.
Arabidopsis/genetics* ; Gene Expression Regulation, Plant ; Gossypium/genetics* ; Lycopersicon esculentum ; Plant Growth Regulators/metabolism* ; Trichomes/genetics*

One hundred and sixty-eight genotypes of cotton from the same growing region were used as a germplasm group to study the validity of different genetic distances in constructing cotton core subset. Mixed linear model approach was employed to unbiasedly predict genotypic values of 20 traits for eliminating the environmental effect. Six commonly used genetic distances (Euclidean, standardized Euclidean, Mahalanobis, city block, cosine and correlation distances) combining four commonly used hierarchical cluster methods (single distance, complete distance, unweighted pair-group average and Ward's methods) were used in the least distance stepwise sampling (LDSS) method for constructing different core subsets. The analyses of variance (ANOVA) of different evaluating parameters showed that the validities of cosine and correlation distances were inferior to those of Euclidean, standardized Euclidean, Mahalanobis and city block distances. Standardized Euclidean distance was slightly more effective than Euclidean, Mahalanobis and city block distances. The principal analysis validated standardized Euclidean distance in the course of constructing practical core subsets. The covariance matrix of accessions might be ill-conditioned when Mahalanobis distance was used to calculate genetic distance at low sampling percentages, which led to bias in small-sized core subset construction. The standardized Euclidean distance is recommended in core subset construction with LDSS method.
Cluster Analysis ; Genetic Variation ; Genotype ; Gossypium ; genetics ; Linear Models ; Principal Component Analysis

Virus isolate G6 was obtained from Hibiscus rosa-sinensis showing yellow and leaf curl symptoms in Guangzhou, Guangdong Province. The complete nucleotide sequence of DNA-A was determined to be 2 737 nucleotides encoding six potential ORFs. Comparison showed that G6 DNA-A had more than 89% sequence identify with all isolates of Cotton leaf curl Multan virus (CLCuMV) and shared the highest sequence identify (96.1%) with CLCuMV isolate 62. G6 DNA-A had 87.1%-89.8% sequence identity with those of CLCuRV isolates, while less than 87% identities with other begomoviruses. Phylogenetic analysis of G6 DNA-A and selected begomoviruses showed that G6 was most closely related to CLCuMV isolates, and they clustered together as a separate branch. Satellite DNA molecule (G6 DNAbeta) was found to be associated with G6 using the primers beta01 and beta02. G6 DNAbeta contains 1346 nucleotides, with a potential functional ORF (C1) in complementary sense DNA. Pairwise comparison indicated that G6 DNAbeta had the highest sequence identities with CLCuMV DNAbeta (92.1%) and CLCuRV DNAbeta (88.7%), but less than 80% sequence identities with other reported satellite DNA molecules. Phylogenetic analysis indicated that G6 DNAbeta was most closely related to CLCuMV DNAbeta and the two DNAbetas clustered together as a separate branch, and formed the main branch with DNAbeta of CLCuRV and MYVV-Y47. It is concluded that G6 infecting Hibiscus rosa-sinensis is an isolate of CLCuMV.
Base Sequence ; DNA, Satellite ; chemistry ; DNA, Viral ; chemistry ; Geminiviridae ; classification ; genetics ; Gossypium ; virology ; Hibiscus ; virology ; Phylogeny

Fluorescence differential display (FDD) technique was used to identify genes that are specifically or preferentially expressed in different developmental stages of cotton fiber cells. One hundred and nine differentially displayed cDNA fragments were isolated using 9, 21 and 27 DPA (days postanthesis) fibers as experimental materials. By a combination of two rounds of reverse Northern hybridization and Northern blot analyses, a number of such cDNA fragments were proved to represent fiber-specific/preferential genes. Sequencing determination and database searching indicated that most of these genes are novel. This work is an important step towards cloning the full-length cDNAs and characterizing the cellular functions of aforementioned genes in fiber development.
Blotting, Northern ; Cotton Fiber ; Fluorescence ; Gene Expression Profiling ; methods ; Gossypium ; genetics ; growth & development ; Polymerase Chain Reaction

The open reading frame of Spinacia oleracea Betaine Aldehyde Dehydrogenase (SoBADH) was retrieved from Spinacia oleracea and inserted into the Agrobacterium tumefaciens binary vector pBin438, which was driven by CaMV35S promoter, and produced the new binary vector pBSB. A. tumefaciens LBA4404 carrying this plasmid was used in genetic transformation of plants. Forty-five primary transgenic plants were detected by PCR and verified by the Southern blotting from 65 regenerated plants, of which 27 transgenic plants had only one copy of T-DNA. The Northern blotting and Western blotting analysis indicated that the SoBADH gene had been transcribed mRNA and expression protein in the transgenic cotton lines. The testing of SoBADH activity of transgenic plant leaves showed that the enzyme activity was much higher than that of the non-transgenic cotton. The growth of transgenic plants was well under the salinity and freezing stress, whereas the non-transgenic plant grew poorly and even died. Challenging with salinity, the height and fresh weight of transgenic plants was higher compared with those of non-transgenic plants. Under the freezing stress, the relative conductivity of leaf electrolyte leakage of the transgenic cotton lines was lower than that of non-transgenic plants. These results demonstrated that the SoBADH gene could over express in the exogenous plants, and could be used in genetic engineering for cotton stress resistance.
Adaptation, Physiological ; Betaine-Aldehyde Dehydrogenase ; biosynthesis ; genetics ; Cold Temperature ; Gossypium ; enzymology ; genetics ; Plants, Genetically Modified ; enzymology ; genetics ; Salinity ; Spinacia oleracea ; enzymology ; genetics ; Stress, Physiological ; genetics

Cloning of flanking sequences of double-copy gene is a challenge in molecular biology. We developed a method to solve this problem by combining an optimized inverse PCR (iPCR) with TAIL-PCR. First, Southern blotting analysis was used to determine a proper restriction enzyme that could obtain proper-length restriction fragments that contained the target gene. Then optimized iPCR was performed to amplify the restriction fragments that contained the separated copies of the gene. Based on the obtained sequences, TAIL-PCR was performed to amplify further flanking regions of the gene. With this method, we obtained all of the EcoR I restriction fragments (2.2-5.1 kb) and Hind III restriction fragments (8.5-11.7 kb) of mitochondrial atpA gene in cytoplasmic male sterile (CMS) line and maintainer line of Upland cotton. The results showed that this method was an efficient approach to clone flanking sequences of double-copy gene.
Chromosome Walking ; Cloning, Molecular ; Gene Expression Regulation, Plant ; Genes, Mitochondrial ; Genes, Plant ; genetics ; Gossypium ; genetics ; Plant Proteins ; genetics ; metabolism ; Polymerase Chain Reaction ; methods ; Terminal Repeat Sequences

Using interval mapping and marker simple regression methods, the QTLs of yield and its components in (Simian 3 x TM-1) F2 and F2:3, were tagged and Mapped with 39 SSR and 10 RAPD markers having polymorphism between parents screened from 301 pair SSR primers and 1040 RAPD primers. Simian 3 is being grown extensively in Yangtze River cotton-growing valley characterized as high productivity with more bolls and higher lint percent, whereas TM-1, Genetic standard in Upland cotton with more heavy boll weight. In the present report, two QTLs controlling boll size with 18.2% and 21.0% phenotype variance explained in F2:3 generation, one QTL controlling lint percent with 24.9% phenotype variance explained in F2 generation and 5.9% in F2:3 generation and one QTL controlling 100-seed weight with 15.6% phenotype variance explained in F2:3 generation were mapped in Chromosome 9. Additionally, another QTL responsible for 100-seed weight was identified and mapped at the same position in Chromosome 9 in F2:3 generation. It is worth for further to be studied whether it is one QTL for pleiotrophism or two closely linked QTLs. The molecular markers mapped and tagged closely with main QTLs of yield traits in this paper can be used for MAS in cotton high-yield breeding program.
China ; Chromosome Mapping ; Crops, Agricultural ; Crosses, Genetic ; Genetic Linkage ; Genetic Markers ; Gossypium ; genetics ; Polymorphism, Single-Stranded Conformational ; Quantitative Trait, Heritable ; Random Amplified Polymorphic DNA Technique

Arabidopsis ; genetics ; growth & development ; microbiology ; Gossypium ; growth & development ; microbiology ; Green Fluorescent Proteins ; Hyphae ; growth & development ; pathogenicity ; Plant Diseases ; genetics ; microbiology ; Plant Roots ; microbiology ; Spores, Fungal ; growth & development ; pathogenicity ; Verticillium ; growth & development ; pathogenicity

Wild cotton species can contribute a valuable gene pool for agronomically desirable cultivated tetraploid cultivars. In order to exploit diploid cotton a regeneration system is required to achieve transformation based goals. The present studies aimed at optimizing the conditions for regeneration of local varieties as well as wild species of cotton. Different callus induction media were tested with varying concentrations of hormones in which sucrose was used as nutritional source. Different explants (hypocotyls, cotyledon, root) were used to check the regeneration of both local cotton plants and wild relatives using T & G medium, BAP medium, CIM medium, EMMS medium, and cell suspension medium. Different stages of embryogenicity such as early torpedo stage, late torpedo stage, heart stage, globular stage and cotyledonary stage were observed in wild relatives of cotton. The results of this study pave the way for establishing future transformation methods.
2,4-Dichlorophenoxyacetic Acid ; Benzyl Compounds ; Cotyledon ; growth & development ; Culture Media ; Gossypium ; embryology ; genetics ; growth & development ; metabolism ; Hypocotyl ; growth & development ; Kinetin ; Naphthaleneacetic Acids ; Plant Growth Regulators ; Purines ; Regeneration ; physiology ; Transformation, Genetic ; Zeatin