جستجوی مقالات مرتبط با کلیدواژه « گلدهی » در نشریات گروه « بیوتکنولوژی و ژنتیک گیاهی »

Most of the garlic clones are non-bolting and sterile and propagate asexually; however, some of the clones are bolting, and there are some fertile clones among the bolting ones. A correct understanding of the MADS-BOX genes family expression pattern and structure, including AGL6, is a valuable project and will improve garlic breeding programs. So far there are no reports relating AGL6 identification as a flowering and fertility integrator gene in garlic. So the aim of this study is to investigate the relative expression of AGL6 in Iranian bolting, semi- and non-bolting garlic clones and to identify its structure and nucleotide sequence.

At first the relative expression of the AGL6 was investigated in the different organs of non-bolting, semi-bolting and bolting Iranian garlic clones using quantitative Real time- PCR. Then the isolation and cloning of the AGL6 partial sequences from the garlic floret was carried out using RT-PCR. The sequence of the recombinant plasmid was evaluated using BLAST, Vector NTI, ORF finder and MEGA6 software.

According to the obtained results, AGL6 was expressed in the meristem, inflorescence, tepal and carpel of green and purple flowers of the bolting garlic. But there was no sign of its expression in the stamen. AGL6 expression level in the meristem of bolting garlic was higher than the meristem of the semi-bolting and non-bolting garlic in all sampling stages, especially in the flowering induction stage. AGL6 was also expressed in the inflorescence of the semi-bolting and bolting garlic, but its expression in the inflorescence of the semi- bolting garlic was 4 times less than the inflorescence of the bolting garlic. Sequence analysis of the colonized fragment showed the coding region with a 728 bp length, which was registered in the NCBI database with the accession number of OK086759.1. This nucleotide sequence encodes a protein with 243 amino acids and has MADS-box and K-box domains. Results showed the high similarity of the sequence obtained in this research with other AGL6 gene homologues in other plant species, especially petaloid monocots such as onion, lily, narcissus and saffron in NCBI. Hence the resulting sequence was named AsAGL6.In this research, for the first time, the expression pattern of a key gene of the flowering and fertility pathway (AsAGL6) and its nucleotide structure were determined in garlic. The results of this research can be effectively used in the design of classical and molecular garlic breeding programs.

The availability of nutrients such as phosphorus in plant, in addition to plant yield increment, could increase growth rate and thus reduce plant growth period. Therefore, identification and overexpression of genes involved in nutrient uptake are the important steps to increase of yield and tolerance to environmental stresses particularly the end seasons stresses. Purple acid phosphatases, one of the most important phosphatase family, play a key role in increasing phosphorus availability in plants. In this study, the effect of knock-out and overexpression of AtPAP17 and AtPAP26 genes (two important members of Arabidopsis thaliana purple acid phosphatase family) on some physiological and phonological traits of Arabidopsis thaliana was investigated under Pi-sufficient (1.25 mM KH2PO4) and Pi-deficient (0 mM KH2PO4) conditions. For this purpose, single and double mutant plants of AtPAP17 and AtPAP26 genes were studied in this research. To confirm the function of mentioned genes in mutant plants, transformed Arabidopsis plants containing the CaMV-35S:AtPAP17 and CaMV-35S:AtPAP26 constructs were studied as overexpressed plants of AtPAP17 and AtPAP26 genes, respectively. The result showed that biomass and phosphorus content of plants increased in single mutant plants as compared to double mutant plants under Pi-sufficient condition. Superiority of single mutant plants as compared to double mutant plants indicated a remarkable contribution of AtPAP17 and AtPAP26 genes in phosphatase compensation network. Our results showed at least one of these genes (AtPAP17 and AtPAP26) activity is essential for increasing phosphorus availability and fast growth in Arabidopsis thaliana. Also, overexpressed plants displayed a significant increase in phosphorus content, flowering percentage, and biomass as compared to WT plants (Col-0). The results of this study showed that AtPAP17 and AtPAP26 genes could be important candidates for developing the plants with high ability of nutrient uptake, especially phosphorus, thereby reducing plant growth period.

The transition from the vegetative phase to reproductive phase is the most important event in production and genetic innovation. This phenomenon is influenced by many genetic and environmental factors in plants. According to studies carried out in this field, one of the environmental factors affects the reproductive and flowering process is Trichoderma species, which is abundant in soil. This study was carried out to evaluate the ability of two recombinant Trichoderma harzianum strains containing chimeric chit 42 (with CHBD domain) and wild-type strain to promote common bean flowering and yield increase in vivo condition. To do this, flowering parameters such as a number of flowers, flowering time and effective parameters in yield were evaluated. Also, expression level of some flowering-related genes such as FT and SOC1 were measured using real-time PCR. The results showed that the bean plants treated with recombinant strains had a significantly increased number of flowers and earlier flowering compared to the control and wild type Trichoderma. Also, plants treated with recombinant strains showed a significant difference in the number and weight of the pod compared to the plant treated with wild type strain and non-treated plants. In addition, the plants treated with T13 strain showed more expression levels of the FT and SOC1 genes (with ratio of 3.42 and 3.41 fold respectively) compared to other treatments and control plant. Finally, T13 recombinant strain exhibited a better performance compared to the other strains through a positive effect on flowering and then increased the crop yield.

Flower initiation is an important factor influencing plant yield. Environmental factors significantly affect flowering initiation. Bioinformatic analysis was performed on MADS-box transcription factors which are considered as important components in the flower formation. Brachpodium is a new experimental model which used to understand the genetic, cellular mechanism and molecular biology of plants. In this study, 43 sequences of Brachypodium MADS-box genes were analyzed using phylogeny relationships, conserved motifs, chromosomal location, detection of transcription factor binding sites, and amino acid composition. The aim of this study was to better identify molecular mechanisms related to flowering. In this study, results showed that MADS-box genes distribute on all Brachypodium chromosomes, while gene clusters were located on all chromosomes except chromosome five. Analysis of the amino acid composition revealed that lucine, serine, and glutamate, with the highest amount, and tryptophan, with the least amount, elicit appreciable flowering. Based on the phylogeny analysis the genes were divided to four clusters. Tajima test indicated the presence of balancing selection in MADS-box sequences and as a result polymorphism is conserved in the sequences. Thus, the total diversity in MADS-box genes were high. Overall, our results provided useful information for the survey of flowering response genes, thereby detection of molecular mechanism and intergenic relationships facilitate flowering pathway.

Environmental conditions lead to biosynthesis of signaling molecules including phytohormones in plants which have important functions as primary messengers in signal transduction and regulating cell metabolism. Jasmonic acid hormone by controlling the transcription factors can play key roles in response to various stresses and developmental processes in plants. Despite numerous studies, plant responses to the hormone are not completely understood. Here, microarray data of Arabidopsis from GEO database was used for analysis of co-expression network. WGCNA (Weighted Gene Co-expression Network Analysis) analysis determines 25 gene groups (modules) that their expression profiles correlated highly significant with each other in response to jasmonic acid. Gene ontology was utilized to investigate each module for statistical significance. This analysis indicated that jasmonic acid controls many processes including photosynthesis, cell programmed death, and response to various stresses. In addition, many of transcription factors such as 11 genes of NAC family and 12 genes of bHLH family play roles in the regulation of jasmonic acid responses and adjust processes including response to biotic and abiotic stresses, flower development and response to light.

The control of flowering time requires activation of a cascade of successive genes which are affected by several internal and external factors. Some of these genes, such as Curly Leaf (CLF), have inhibitory effect on flowering. Thus, by silencing of these genes, initiation of flowering can be accelerated. In this research, the RNA Silencing technology is used to investigate the possibility of production of early-flowering plants via CLF silencing. First, in order to produce hairpin structure, a fragment of CLF gene of Arabidopsis thaliana was amplified by PCR and then cloned in two sense and antisense directions, into pFGC5941 vector. The resulted recombinant vector was then transferred into Arabidopsis plants via Agrobacterium method. As expected, initiation of flowering was accelerated in transgenic plants in comparison with the wild-type plants. In agreement to the obtained results, RTqPCR analysis showed that CLF expression in transgenic plants was decreased in comparison with the wild-type plants. In contrast, FT (a gene which induces flowering) expression was increased in transgenic plants. These results show that RNA silencing as a novel and timesaving biotechnological method could be applied to generate early-flowering plants.