Responses of MxPPO overexpressing transgenic tall fescue plants to two diphenyl-ether herbicides, oxyfluorfen and acifluorfen

Abstract

We generated transgenic tall fescue (Festuca arundinacea Schreb. cv. Kentucky-31) plants harboring a synthetic Myxococcus xanthus protoporphyrinogen oxidase (MxPPO) gene through Agrobacterium-mediated gene transfer. Successful integration of the transgene into the genome of transgenic plants confirmed by polymerase chain reaction (PCR) and Southern blot analysis, and the functional expression of the MxPPO gene at the mRNA level in transgenic lines was validated by Northern blot analysis. Responses of transgenic and non-transgenic tall fescue plants to diphenyl-ether herbicides such as oxyfluorfen and acifluorfen have been evaluated in respect of various physiological and biochemical parameters. Differential responses were observed in chlorophyll content, in vivo H 2 O 2 deposition and lipid peroxidation in both transgenic and non-transgenic plants exposed to oxyfluorfen or acifluorfen. Isozyme profiles of four antioxidantenzymes, including peroxidase (POD), catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX), were also investigated in transgenic and nontransgenic plants using native PAGE analysis. Compared to the transgenic lines, higher staining activities of the examined antioxidant-enzymes observed in non-transgenic plants subjected to 100 lM of oxyfluorfen or acifluorfen suggests that non-transgenic plants are unable to prevent the photodynamic induced oxidative stress caused by herbicides. In addition, both transgenic and non-transgenic plants exposed to oxyfluorfen exhibited proportionally increased band-staining patterns in contrast to acifluorfen, which suggests that oxyfluorfen has relatively greater or more rapid effects on leaves than acifluorfen.

Overexpression of a chloroplast-localized small heat shock protein OsHSP26 confers enhanced tolerance against oxidative and heat stresses in tall fescue

“…Biotechnological approaches have the potential to complement or accelerate conventional breeding by extending the range of sources for valuable traits, thus offering new opportunities for tall fescue improvement. Indeed, the molecular breeding of tall fescue for tolerance to herbicides (Lee et al 2008), salt, and drought (Cao et al 2009;Zhao et al 2007) has been reported. The stress-inducible expression of two antioxidant genes (CuZnSOD and APX) simultaneously able transgenic plants to tolerate a wide range of abiotic stresses, including methyl viologen (MV), H 2 O 2 , and heavy metals (Lee et al 2007).…”

Development of antibiotic marker-free creeping bentgrass resistance against herbicides

“…ELISA assays ELISA assays were used to quantify CP4-EPSPS protein, essentially as described previously [16]. Leaf samples from non-transgenic plants and independent transgenic lines were collected.…”

“…Milli-Q water was used as a control. The treatment procedure was performed according to that described by Lee et al [16]. The plants were observed over 1 week to determine resistance or susceptibility to the herbicide.…”

Improved embryogenic callus induction and plant regeneration in big bluestem (Andropogon gerardii Vitman), a potential bioenergy feedstock

“…Chen et al (1977) and Chen and Boe (1988) The objective of this study was, therefore, to establish an efficient regeneration system from the calli of mature seeds in big bluestem cultivars, Kaw and Earl, that are well adapted to the southern US. Mature seeds are considered an important source of explants, as they are readily available and used frequently for in vitro regeneration (Li et al, 2009a;Lee et al, 2006Lee et al, , 2008.…”