Crop Biotechnology
Year:2020 | Volume:9 | Issue:28|Papers Count:6

Conventional pBI121-based binary vectors are widely used in transformation of higher plants mediated by Agrobacterium but they are useless in transformation of some monocots because of inefficiency of kanamycin in selection, while, hygromycin resistance gene is an important selectable marker that usually used in transformation of several plants, especially monocots. The aim of this study was to improve the pBI121 vector for transformation of monocot plants. For this purpose, the hygromycin resistance gene with the 35S terminator were isolated from p6-ubi-rnai plasmid and cloned into pBlueScript intermediate vector via SmaІ and NotI restriction enzyme digestion. The CaMV 35 promoter was isolated from pBI121 vector by using SmaI and HindIII enzymes and cloned upstream of the gene. By using HindIII and Eco53KI enzymes, the complete hygromycin resistance gene cassette was replaced the kanamycin resistance gene cassette (which digested by HindIII and MssI) of pBI121 vector. Construction of this vector was confirmed by PCR method, digestion pattern analysis, and sequencing. Due to the popularity of pBI121-based vectors than other binary vectors and the researchers' familiarity with their manipulation, the vector which is introduced in this study could be used in gene transfer studies of monocot plants.

Trigonella foenum-graecum is annual plant and dicotyldones of the fabaceae family. Root, leaf and seed have important medicinal compounds. Manipulation of cell culture media with elicitors is one of the important strategies for induction of secondary metabolism and production of valuable metabolites. Salicylic acid as a non-biological elicitor is effective in increasing the production of pharmaceutical metabolites. The aim of this study was to investigate the effect of salicylic acid on growth, some physiological and trigonelline production in in vitro culture of fenugreek. Fenugreek cell culture was obtained using cuticle extract of TN-47-155 fenugreek genotype in MS medium containing 0. 35 mg / l TDZ and 0. 05 mg / l IBA. Salicylic acid at concentrations of 12. 5, 25, 50 mg / L were used. The cells were then treated with triglyceride and other physiological parameters after one week of treatment. The results of HPLC showed that cell growth and viability of the cells decreased as compared to the control. The amount of hydrogen peroxide and membrane lipid peroxidation in the cells increased compared to the control (without hormone) treatment. All treatments increased the production of TG and total phenol. Treatment of cells with 50 mg / l (75%) salicylic acid increased triglyceride levels twice as much as control (35%). Salicylic acid can be used as a stimulant in fenugreek cell culture and induces higher triglyceride production.

Identification of the linked markers to drought tolerance genes are needed for the breeding of rice varieties. In order to mapping of QTLs controlling related to drought tolerance, 96 rice Inbred lines caused Ahlamitarom × Neda cross planted as complementary randomized design with 3 replications under drought stress in Gonbad Kavous University lab in 2014. Given the genetic variation among the studied lines, it was possible to the detection of QTLs in this study. In calculating the correlation of traits evaluated under drought stress, the highest correlation was for root diameter with root area density (0. 96 **). The results of cluster analysis based on total traits under drought stress, lines assigned to four groups: tolerant, semi-tolerant, semi-sensitive and sensitive. Linkage map provided using F8 population, 30 SSR markers, and 20 ISSR markers and covered 1413. 2 cM with an average distance between two markers 12. 18. QTL analysis indicated that containing totally 13 distances were found, in this way, 2 QTL stem length, 1 QTL root number, 3 QTL leaf width, 1 QTL stem weight, 3 QTL leaf surface, 1 QTL stomata density before stress, 1 QTL stomata density after stress, 1 QTL ratio of total stomata surfaces total area after stress were controlled. Of the detected QTLs, qLL-2 and qSA-12, explained a high percentage of phenotypic variation for leaf area and stomata density after stress. The major QTLs detected in this study, can be used in marker-assisted selection breeding programs after validation.

In higher plants, sucrose synthase (SuS, EC 2. 4. 1. 13) is widely considered as a key enzyme involved in sucrose metabolism and catalyzes the reversible cleavage of sucrose into fructose and UDP-glucose. Here, 22 SuS genes have been identified in the genome of wheat by using bioinformatics methods and renamed TaSUS1 to TaSUS22 according to their chromosomal locations. Phylogenetic analysis revealed that the sucrose synthase genes in wheat and other plants were divided into three evolutionary groups, named SUS I, SUS II and SUS III, respectively. SuS genes in the same group showed similar structural characteristics, such as exon number, size and length distribution. The upstream regions of TaSuS genes had variable frequencies of cis-regulatory elements that could show regulation at different developmental stages and/or differential regulation in response to stress, while 21 genes had targets for 16 different miRNA families that show the importance of posttranscriptional regulation for TaSUS genes. Temporal and spatial expression profiling indicates a potential role for SUSI genes during growth and development in wheat. These results give new insights into the evolution and basic information that will aid in elucidating the functions of the wheat SuS gene family.

The co-existence of plant and bacteria with nodule formation and nitrogen fixation has a great effect on plant production, as well as plant protein content. In this study, 194 strains of semi-symbiotic Rhizobium leguminosarum were used to identify bacterial genes related to nodule formation on Lotus burttii. Nodule related traits (number of white nodes, number of pink nodes, and total number of nodes) were measured at 7, 14, 21 and 28 days after inoculation. Principal Component Analysis (PCA) showed complete separation between strains with genomes A, C and D. In addition, the results of genome-wide association study (GWAS) showed that operon with secretory factor activity is effective in inducing resistance to red node trait.

Environmental stresses have an irreversible effect on the production of bread wheat (Triticum aestivum L. ), one of the most important crop plants. On the other hand, AP2/ERF members are the most important transcriptional regulators that influence plant growth and response to biotic and abiotic stresses. To evaluate the mechanism of salt stress tolerance in wheat the activities of superoxide dismutase, ascorbate peroxidase and catalase in two tolerant wheat landraces (3623 and 3625) under salinity were investigated by completely randomized factorial experiment at control and 250 mM salinity in three replications. Seedlings were sampled at 0, 1, 3, 6, 12 and 24 h and 10 days after stress. The activity of enzymes was measured in the root and shoot of plants. The AP2-21 nucleotide sequence was extracted from the NCBI database and primers were designed and the gene fragment was isolated from wheat and then cloned and sequenced and confirmed by the presence of AP2 conserved domain. TaAP2-21 expression was evaluated by qPCR using specific primers and β-actin housekeeping genes. The results showed a significant difference in enzyme activity at different times compared to control in both tissues of both landraces and the highest was observed in short and medium-term stresses, however, apparently in long term stress the antioxidant mechanism of the enzymes is more active in 3623 than in 3625. Gene expression decreased significantly under salinity in both tissues. The TaAP2-21 gene is probably one of the inhibitors of the transcription of saline responsive genes and causes salt sensitivity in wheat.