棉花GhGAI1基因克隆及其功能的初步分析

DELLA蛋白是赤霉素信号通路中重要的蛋白质作用因子,负调节植物体中赤霉素的水平,同时受到生长素、脱落酸和乙烯的共同调节。根据已知的生物信息数据,本研究克隆了棉花GhGAl1基因,序列分析表明它编码DELLA蛋白。构建GFP与GhGAl1融合蛋白重组质粒,利用根癌农杆菌介导的花浸泡转基因方法转化拟南芥columbia生态型植株,进行过量表达实验。结果表明,GFP—GhGAl1融合蛋白定位于细胞核并且在施加赤霉素后迅速降解,表明该基因编码蛋白参与赤霉素信号通路。     

Fine mapping of the red plant gene R_1 in upland cotton (Gossypium hirsutum)

Sub 16 is a substitution line with G. hirsutum cv. TM-1 genetic background except that the 16th chro-mosome (Chr. 16) is replaced by the corresponding homozygous chromosome of G. barbadense cv. 3-79, and T586 is a G. hirsutum multiple gene marker line with 8 dominant mutation genes. The R1 gene for anthocyanin pigmentation was tagged in Chr. 16 in T586. The objective of this research was to screen SSR markers tightly linked with R1 by using the F2 segregating population containing 1259 plants derived from t...     

Plants are better protected against spider-mites after exposure to volatiles from infested conspecifics

When infested by herbivorous mites, cotton seedlings produce volatile cues that elicit attraction of predatory mites. Experiments were carried out to elucidate how downwinduninfested conspecific seedlings are affected by these volatiles. It was found that the rate of oviposition of herbivorous mites was reduced on seedlings exposed to volatiles from infested seedlings. Moreover, predatory mites were attracted by exposeduninfested seedlings. These results strongly suggest that uninfested plants are better protected against herbivore attack when exposed to airborne chemicals released by their infested neighbours.     

棉花花粉发育过程中同工酶的研究

本文利用超薄胶电泳技术对陆地棉（ＧｏｓｓｙｐｉｕｍＨｉｒｓｕｔｕｍＬ．）花粉发育各期的酯酶的过氧化物酶的同工酶活性变化进行了研究，结果发现，在花粉第一次有丝分裂结束之前，存在大量的低分子量酯酶和过氧化物酶，花粉成熟后又新出现了一些大分子量酯酶的过氧化物酶，提示：花粉的发育过程是一个基因差异表达的过程，并受一定的机制控制．     

Cloning and sequence analysis of a gene encoding polygalacturonase-inhibiting protein from cotton

Polygalacturonase-inhibiting proteins (PGIP) play important roles in plant defense of pathogen, especially fungi. A pair of degenerated primers is designed based on the conserved sequence of 20 other known pgip genes and used to amplify Gossypium barbadense cultivation 7124 cDNA library by touch-down PCR. A 561 bp internal fragment of the pgip gene is obtained and used to design the primers for rapid amplification of cDNA ends. A composite pgip gene sequence is constructed from the products of 5′ and 3′ RACE, which are 666 bp and 906 bp respectively. Analysis of nucleic acid sequence shows 69.2% and 68.7% similarity to Citrus and Poncirus pgip genes, respectively. Its open reading frame of the gene encodes a polypeptide of 330 amino acids, in which 10 leucine-rich repeats arrange tandemly. A new set of primers is designed to the 5′ and 3′ ends of the gene, which allows amplification of the full-length gene from the cotton cDNA library. Genomic DNA analysis reveals that this gene has no intron.     

Evaluation of the introgressed lines and screening for elite germplasm in Gossypium

THERE ARE 51 SPECIES IN THE GENUS OF GOSSYPIUM[1]. EXCEPT UPLAND COTTON CULTIVARS, WILD CULTIVARS, SPECIES AND RACE HAVE ABUNDANT GENETIC POLYMORPHISMS DUE TO THEIR VARIOUS ENVIRONMENTAL DISTRIBUTION AND LONG-TERM NATURAL SELECTION. THEREFORE, THEY POSSESS LOTS OF EXCEL- LENT GENES THAT CAN BE USED TO EXPLOIT POTENTIAL TRAITS, SUCH AS DROUGHT RESISTANCE, DISEASE AND INSECT …     

Effect of GbKTN1 from Gossypium barbadense on cell elongation of fission yeast（Schizosaccharomyces pombe）

The GbKTN1 gene was isolated from 10 DPA fiber cells of Gossypium barbadense using 5′RACE/3′RACE.Full-length cDNA of this gene is 2006 bp, including a 113 bp of 5′untranslated region, a 1563 bp of an open reading frame(ORF), and a 327 bp of 3′untranslated region (excluding the stop codon TAA). The ORF of GbKTN1 encodes a 521-amino acid protein with a predicted size of 55 kD. Near C-terminal of the deduced protein there is a putative ATP binding site between amino acid residues from 233 to 414. Southern blot analysis indicated that the GbKTN1 was a single copy gene in G barbadense. Combining semi-quantitative RT-PCR with Southern blot hybridization revealed that GbKTN1 expressed in all the organs detected such as roots, stems, leaves and fibers. However, the mRNA of GbKTN1 was the most abundant in fiber cells, while it was the lowest in leaves. The GbKTN1 cDNA was transformed into S. pombe to verify its function on cell elongation. Results showed that most yeast cells over expressing GbKTN1 gene were elongated dramatically with an average length increase of 2.18 times than that of the non-induced cells. Even the morphology of some yeast cells appeared irregularly. To the best of our knowledge this is the first evidence that KTN1 is correlated with cell elongation in vivo.     

陆地棉LTR反转录转座子的数量分布与功能分析

LTR(Long terminal repeat)反转录转座子是真核生物基因组中普遍存在的一类遗传因子,它们以RNA为媒介在基因组中不断自我复制.在高等植物中,LTR反转录转座子是基因组的重要成分之一.本研究通过多种方法挖掘并注释了陆地棉基因组中的LTR反转录转座子,结果表明陆地棉基因组LTR反转录转座子的Gypsy超家族与基因的分布呈近似的反比关系,而Copia超家族在各染色体的起始端有较多的分布.通过皮尔森相关系数发现陆地棉LTR反转录转座子的拷贝数与染色体大小之间有强相关性.在LTR反转录转座子上游和下游分布的基因具有类似的富集特征,其分子功能主要集中在结合和催化活性等方面.本研究结果加深了对陆地棉LTR反转录转座子的认识,为深入研究棉花基因组提供了重要数据支撑.     

Identification of RAPD marker linked with fertility-restoring gene of cytoplasmic male sterile lines in upland cotton

Bulked segregant analysis was employed to construct two mixed DNA pools to screen the RAPd marker linked with the fertility-restoring gene(Rf _i) of upland cotton. A total of 425 arbitrary 10-mer oligonucleotide primers were screened on two DNA pools, bulked male fertile and sterile DNAs isolated from BC₃ segregating population of (0-613-2R X Simian No. 3). Three primers produced repeatable polymorphisms between the paired bulks and their parents. DNA was extracted and amplified with these three primers for 92 plants of (Zhong 12A-1 × 0-613-2R)F₂. Based on the male fertility scoring and RAPD amplification, it is found that one RAPD marker fragment designated OPV-15₃₀₀ was linked with the fertility-restoring gene (Rf₁) with a recombination value of 13.0±2.57%.