Greenhouse and field testing of transgenic wheat plants stably expressing genes for thaumatin-like protein, chitinase and glucanase against Fusarium graminearum

Abstract

Genes encoding pathogenesis-related (PR-) proteins isolated from a cDNA library of Fusarium graminearum-infected wheat spikes of scab-resistant cultivar 'Sumai-3' were transformed into susceptible spring wheat, 'Bobwhite' using a biolistic transformation protocol, with the goal of enhancing levels of resistance against scab. Twenty-four putative transgenic lines expressing either a single PR-protein gene or combinations thereof were regenerated. Transgene expression in a majority of these lines (20) was completely silenced in the T(1) or T(2) generations. Four transgenic wheat lines showed stable inheritance and expression of either a single transgene or transgene combinations up to four generations. One line co-expressing a chitinase and beta-1,3-glucanase gene combination, when bioassayed against scab showed a delay in the spread of the infection (type II resistance) under greenhouse conditions. This line and a second transgenic line expressing a rice thaumatin-like protein gene (tlp) which had moderate resistance to scab in previous greenhouse trials, along with susceptible and resistance checks were evaluated for resistance to scab under field conditions. None of the transgenic lines had resistance to scab in the field under conditions of strong pathogen, suggesting these plants lacked effective resistance to initial infection (type I resistance) under these conditions. As far as is known, this is the first report of field evaluation of transgenic wheat expressing genes for PR-proteins against disease resistance.

Enhancing lignan biosynthesis by over‐expressing pinoresinol lariciresinol reductase in transgenic wheat

“…'Bobwhite', 'Madison', and 'Fielder', respectively). The method of co-transformation and selection of transgenic events have been described by Anand et al [27]. Briefly, the premature seeds were surface sterilized with 20% sodium hypochlorite and 0.02% TWEEN-20.…”

“…To examine the expression of the selectable bar resistance gene in the transgenic plants, leaf planting was done as previously described [27]. Briefly, freshly prepared solution of herbicide, LibertyP ® Pat 0.2% (v/v) was applied on the second/third youngest leaf using a cotton plug.…”

Purification, characterization of a CkChn134 protein from Cynanchum komarovii seeds and synergistic effect with CkTLP against Verticillium dahliae

“…Early research in other plants had indicated synergistic protective interaction of the coexpression PR proteins. [6][7][8][9][10][11][12] Coexpression chitinase and b-1,3 glucanse by placing both genes in the same T-DNA improved the resistance of tobacco against R. solani. 8 Chitinase and b-1,3 glucanse genes coexpressed in carrot reduced the disease severity caused by Alternaria dauci, A. radicina, C. carotae, and Erysiphe heraclei.…”

“…5 To effectively inhibit fungal growth and significantly enhance protection against fungal attack in plants, expression of chitinase genes in combination with other PR-proteins has been reported, which indicated synergistic protective interaction of the coexpressed antifungal proteins. [6][7][8][9][10][11][12] Hybrid tobacco with rice basic chitinase and alfalfa acidic glucanase genes showed at least 75% reduction in the number of lesions produced by Cercospora nicotianae. 7 Transgenic tobacco with barley chitinase and b-1,3 glucanase genes showed enhanced resistance to R. solani.…”

“…11 Coexpression chi11 and glucanase genes in wheat plants could delay Fusarium head blight development. 12 The experimental evidences are an encouraging attempt toward genetically engineered disease resistance in chitinase and glucanase in varieties of agriculturally important crops. However, not much is known about the synergistic effect of chitinase with thaumatin-like, which will be further studied by transgenic Arabidopsis with CkChn134, a new protein in chitinase family identified from Cynanchum komarovii.…”