Life Sciences Commons^™

Identification And Characterization Of Isoflavone Reductase Family Members In Soybean, Negin Azizkhani

Electronic Thesis and Dissertation Repository

Soybean’s yield is threatened by Phytophthora sojae, a pathogen responsible for stem and root rot disease. Glyceollins, unique antimicrobial agents specific to soybeans in partially preventing P. sojae infection, are derived from the isoflavonoid branch of the general phenylpropanoid pathway. One pivotal enzyme exclusively involved in glyceollin synthesis in soybean is the isoflavone reductase (GmIFR), which catalyzes the 2'-hydroxydaidzein conversion to 2'-hydroxy-2,3-dihydrodaidzein as a precursor for glyceollin biosynthesis. To comprehensively identify all members of the GmIFR gene family within the soybean genome, keyword and blast protein searches were conducted, identifying 98 putative GmIFRs. Among these candidates, …

Soybean Root Exudates Increase The Physiological Diversity Of Bacteria In Cadmium-Treated Soil, Leily Kazemi Movahed

Electronic Thesis and Dissertation Repository

Three soybean cultivars with contrasting retention of cadmium (Cd) in the root were grown in Cd-spiked nutrient solution and used to determine that symplastic compartmentalization of Cd in roots is probably responsible for retention of Cd in roots. Roots of the low Cd-accumulator AC Hime treated with 30 mM Cd exuded up to 10-fold higher concentrations of citric, succinic, fumaric and malic acids into the hydroponic solution when compared to control; concentrations of the same organic acids from the high Cd-accumulator Westag 97 increased by up to 3-fold. The same cultivars were grown in Cd-spiked soil and the physiological profiles …

Gmmyb176 Interactome And Regulation Of Isoflavonoid Biosynthesis In Soybean, Arun Kumaran Anguraj Vadivel

Electronic Thesis and Dissertation Repository

MYB transcription factors are one of the largest transcription factor families characterized in plants. They are classified into four types: R1 MYB, R2R3 MYB, R3 MYB and R4 MYB. GmMYB176 is an R1MYB transcription factor that regulates Chalcone synthase (CHS8) gene expression and isoflavonoid biosynthesis in soybean. Silencing of GmMYB176 suppressed the expression of the GmCHS8 gene and reduced the accumulation of isoflavonoids in soybean hairy roots. However, overexpression of GmMYB176 does not alter either GmCHS8 gene expression or isoflavonoid levels suggesting that GmMYB176 alone is not sufficient for GmCHS8 gene regulation. I hypothesized that GmMYB176 acts cooperatively with another …

Identification And Characterization Of The Isoflavonoid-Specific Prenyltransferase Gene Family To Prevent Stem And Root Rot In Soybean, Arjun Sukumaran

Electronic Thesis and Dissertation Repository

Soybean is one of the most predominantly grown legumes worldwide, however, one deterrent to maximizing its yield is the pathogen, Phytophthora sojae, which causes stem and root rot disease. Many strategies have been implemented to combat this pathogen such as use of pesticides and certain agricultural practices. However, these have been largely ineffective in completely preventing P. sojae infection. An alternative strategy would be to improve the innate resistance of soybean by promoting increased glyceollin production. Glyceollins are soybean-specific antimicrobial agents which are derived from the isoflavonoid branch of the general phenylpropanoid pathway. Soybeans produce 3 forms of glyceollin: …

Planting The Chalcone Reductase Family Tree: Identification And Characterization Of Chalcone Reductase Genes In Soybean, Caroline Julia Sepiol

Electronic Thesis and Dissertation Repository

Soybean (Glycine max [L.] Merr) is an important crop grown in Canada, generating $2.4 billion in sales. Though this number may be promising, soybean farmers lose about $50 million worth of yield annually due to root and stem rot disease caused by Phytophthora sojae. Many strategies have been developed to combat the infection; however, these methods are prohibitively expensive. A ‘cost effective’ approach to this problem is to select a trait naturally found in soybean that can increase resistance. One such trait is the increased production of root glyceollins. One of the key enzymes exclusively involved in glyceollin …

Soybean Isoflavonoid Biosynthesis: Constituents And Circumstance At The Transcriptomic And Molecular Levels, Mehran Dastmalchi

Electronic Thesis and Dissertation Repository

Isoflavonoids are specialized metabolites, almost exclusive to the legume family of plants. They are actors in symbiosis with nitrogen-fixing bacteria and in plant stress response. Isoflavonoids are noted for their human health benefits. Isoflavonoid content in legumes has proven to be a complex trait. The goal of the present research is to determine the mechanisms underlying isoflavonoid biosynthesis in soybean.

The first approach was to unravel the genetic factors of isoflavonoid biosynthesis. A branch-point enzyme of the phenylpropanoid pathway, chalcone isomerase (CHI), catalyzes the reaction producing flavanones, the nucleus for many downstream metabolites such as isoflavonoids. I identified twelve soybean …

Identification Of Cyclophilin Gene Family In Soybean And Characterization Of Gmcyp1, Hemanta Raj Mainali

Electronic Thesis and Dissertation Repository

I identified members of the Cyclophilin (CYP) gene family in soybean (Glycine max) and characterized the GmCYP1, one of the members of soybean CYP. CYPs belong to the immunophilin superfamily with peptidyl-prolyl cis-trans isomerase (PPIase) activity. PPIase catalyzes the interconversion of the cis- and trans-rotamers of the peptidyl-prolyl amide bond of peptides. After extensive data mining, I identified 62 different CYP genes in soybean (GmCYP1 to GmCYP62), of which 8 are multi-domain proteins and 54 are single domain proteins. At least 25% of the GmCYP genes are expressed in soybean. GmCYP1 …