Molecular biology and (trans) gene expression technology in plant breeding
Dariush Taghavi; Mohammad Majidi; Saeed Mollaei; Bahman Panahi
Abstract
Shikonin is a naphthoquinone with some important medicinal properties and is found in gromwell plant. There are so many biotechnological approaches proposed for the productivity enhancement, and elicitation is recognized as one of the most effective strategies for increasing the production of secondary ...
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Shikonin is a naphthoquinone with some important medicinal properties and is found in gromwell plant. There are so many biotechnological approaches proposed for the productivity enhancement, and elicitation is recognized as one of the most effective strategies for increasing the production of secondary metabolites in plant in vitro cultures. Moreover, a deeper understanding of the mechanisms and factors affecting shikonin biosynthesis can led to the design of more intelligent and efficient biological production systems. To this aim, in the present study, the expression of some genes related to the shikonin biosynthetic pathway including PAL, 4CL, HMGR, GPPS and PGT in in vitro cultures of Lithospermum officinale in response to methyl jasmonate (MJ) at different times, were investigated by real-time PCR. The results showed that MJ had a significant effect on increasing gene expression levels in elicited samples compared to control samples. Additionally, we found that the studied genes respond to MJ with different pattern, in which the highest increase in gene expression level was observed for PGT while the lowest increase was observed for GPPS. Maximum and minimum transcript levels were obtained in most genes at 4 and 96 h post-elicitation, respectively. It was also found that phenylpropanoid pathway genes respond better to MJ than terpenoid pathway genes. The results of the present study would increase our knowledge about elicitor signal transduction pathways, and may be particularly useful for enhancement of shikonin production in plant cell cultures of L. officinale.
Genetic engineering & plant breeding
Masumeh Dezhabad; Hengameh Taheri; Babak Pakdaman Sardrood
Abstract
Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. lycopersici (FOL) is one of the major devastating diseases of tomato plants throughout the world. There is no information on the molecular response of tomato line, Early Urbana-Y to FOL. The present study was performed to study the line response ...
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Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. lycopersici (FOL) is one of the major devastating diseases of tomato plants throughout the world. There is no information on the molecular response of tomato line, Early Urbana-Y to FOL. The present study was performed to study the line response to FOL using phytopathological (disease severity and shoot fresh weight) as well as molecular methodologies. The transcription of several genes responsive to jasmonic acid (JA; Pin2), salicylic acid (SA; Chi3, Chi9 and PR1), the regulatory genes responsive to the signaling hormone JA (MYC2 and WRKY33) and ethylene (ET; ERF1) were studied by qRT-PCR technique at different time points after FOL inoculation (6-96 hour after inoculation). Disease symptoms development and reduced shoot fresh weight of the inoculated plants despite up-regulation of SA-dependent defense genes at different time points after pathogen infection indicated that SA signaling pathway is involved in the susceptibility of the Early Urbana-Y line to FOL. In contrast, JA and ET pathway genes were not strongly induced in response to the pathogen suggesting the involvement of JA/ET-mediated defense responses in reducing disease susceptibility. However, to gain a better understanding of enhanced resistance to fusarium wilt, more detailed molecular mechanisms underlying susceptibility of Early Urbana-Y line to FOL need to be further investigated in the future.
Plant breeding for abiotic & biotic stresses
Nayer Mohammadkhani; Reza Heidari; Nasser Abbaspour; Fatemeh Rahmani
Abstract
Molecular information of K+ accumulation in grapes is strongly required. Under salinity condition potassium transporters are inhibited by Na+. The aim of this study was to investigate the effects of salinity on the expression of K+ transporter genes in grape. Based on the previous screening study on ...
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Molecular information of K+ accumulation in grapes is strongly required. Under salinity condition potassium transporters are inhibited by Na+. The aim of this study was to investigate the effects of salinity on the expression of K+ transporter genes in grape. Based on the previous screening study on 18 grape genotypes, ‘H6’ and ‘Gharashani’ (tolerant) and ‘Shirazi’ and ‘GhezelUzum’ (sensitive) were selected. Plants were treated with 50 mM NaCl as a critical concentration that was not lethal for grapevine plants. Interestingly, the expression of VvKUP1, VvKUP2 and VvK1.1 genes highly increased in leaves of sensitive genotypes compared to tolerant ones. Also the expression of VvKUP1 and VvKUP2 genes were similar in the leaves of sensitive genotypes. There was a significant positive correlation (P
Plant breeding for abiotic & biotic stresses
Khalil Malekzadeh; Ali Niazi; Farajollah Shahriari-Ahmadi; Amin Mirshamsi-Kakhaki; Mohammad Zare-Mehrjerdi
Abstract
Salinity is one of the most important abiotic stresses that limit crop growth and production. Salt stress influences plants in two ways: by affecting ion toxicity and increasing osmotic stress. Ion homeostasis, the excretion of Na+ and using antioxidant systems are the major strategies of salt tolerance ...
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Salinity is one of the most important abiotic stresses that limit crop growth and production. Salt stress influences plants in two ways: by affecting ion toxicity and increasing osmotic stress. Ion homeostasis, the excretion of Na+ and using antioxidant systems are the major strategies of salt tolerance in plants. Na+ and K+ transporters with enzymes that are involved in detoxification of reactive oxygen species play key roles in salt tolerance in plants. The aim of this study was to investigate the responses of high affinity K+ transporter2;1 gene (HKT2;1) which is involved in regulation of ion homeostasis and L-gulonolactone oxidase (GLOase) which is involved in the ascorbic acid biosynthesis pathway, under different concentrations of NaCl over different time points in Aeluropus littoralis shoots. Results from Real Time PCR data showed that expressions of both genes were influenced by external and internal concentrations of Na+ and the internal K+ content. AlHKT2;1 was significantly upregulated by increasing Na+ concentration at all time points. Furthermore, its highest expression level in shoots occurred after 6 days in 300mM NaCl in shoots which was 25folds more than untreated shoots. AlGLOase expression levels increased 54 h after initiation of salt stress. These results indicate that AlHKT2;1 and AlGLOase respond to different salinity conditions and probably are part of the mechanisms involved in tolerance to high salt concentrations in A. littoralis.
Advanced breeding technologies
Fahime Moloudi; Saeid Navabpour; Hassan Soltanloo; Seyedeh Sanaz Ramazanpour; Hamidreza Sadeghipour
Abstract
Drought stress is one of the serious problems that restricted agronomic plant production worldwide. In molecular level, the harmful effect of drought stress is mostly caused by producing of large amount of reactive oxygen species (ROS). Catalase and Metallothionein genes have a crucial role to mope the ...
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Drought stress is one of the serious problems that restricted agronomic plant production worldwide. In molecular level, the harmful effect of drought stress is mostly caused by producing of large amount of reactive oxygen species (ROS). Catalase and Metallothionein genes have a crucial role to mope the hydrogen peroxide (H2O2) resulting reducing oxidative damage. In this research the gene expression pattern of Catalase and Metallothionein was studied in response to drought stress treatments. The treatments included - 0.3 bar, - 0.9 bar, - 8 bar and -12 bar and wheat varieties included Zagros (drought tolerant), Moghan (semi- tolerant) and Tajan (drought sensitive). The amount of cellular oxidative levels (TBARM) increased steady by intensify of drought stress levels. Real time PCR analysis showed different expression pattern for catalase and metallothionein encoded genes. Catalase gene expression was increased during drought stress up to -8 bar and reduced in -12 bar treatment, in all cultivars specially in Tajan cultivar. Metallothionein gene expression was linearly reduced during different levels of drought treatments especially in Zagros and Tajan cultivars. The most activity for both genes has observed in Zagros cultivar at -0.9 bar treatment. Whereas, Moghan cultivar showed most transcription for both genes at -8 bar treatment. Overall gene activities, content of chlorophyll (a, b) and whole plants appearance declined by high level of drought stress e.g. -12 bar treatment in all cultivars particularly in Tajan variety. Whereas, the moderate levels of drought stress treatments induced genes activitiy.