Different mutations in the ZmCAD2 gene underlie the maize brown-midrib1 (bm1) phenotype with similar effects on lignin characteristics and have potential interest for bioenergy production

The maize ZmCAD2 gene has been fully sequenced in several normal and bm1 maize lines, highlighting a large diversity of mutations underlying the bm1 phenotype. Mutations in three bm1 lines (F2bm1, A619bm1, and 511Jbm1) were found corresponding to short InDels inducing premature stop codons and truncated proteins. In two lines (511Kbm1 and 5803Cbm1), mutations were limited to an only SNP or to a few SNP, modifying the catalytic sites, and likely inactivating the proteins. Results also established that the 5803Ibm7 mutant was in fact a bm1 mutant, with a sequence fully identical to the 5803Cbm1 sequence. The two new F7803bm1 (natural mutant) and Ev2210bm1 (transposon tagging Mutator investigations) both had a transposon insertion in the ZmCAD2 DNA, resulting in a truncated protein, even if the mRNA was produced. The biochemical characteristics of the Ev2210bm1 lignins corroborated the signature of CAD2 deficiency in plants, with the presence of aldehydes and atypical compounds and linkages. Considering lignin structure and content, CAD2 is likely a good target for the improvement of energy production based on maize and grass lignocellulosic biomass, including a greater susceptibility to environmentally friendly pretreatments, as it was shown in bmr sorghum. The interest in maize bm1 hybrids for cattle feeding also should be considered because there seem to be little or limited negative effects of CAD2 mutations on other agronomical traits

Different mutations in the ZmCAD2 gene underlie the maize brown-midrib1 (bm1) phenotype with similar effects on lignin characteristics and have potential interest for bioenergy production

The maize ZmCAD2 gene has been fully sequenced in several normal and bm1 maize lines, highlighting a large diversity of mutations underlying the bm1 phenotype. Mutations in three bm1 lines (F2bm1, A619bm1, and 511Jbm1) were found corresponding to short InDels inducing premature stop codons and truncated proteins. In two lines (511Kbm1 and 5803Cbm1), mutations were limited to an only SNP or to a few SNP, modifying the catalytic sites, and likely inactivating the proteins. Results also established that the 5803Ibm7 mutant was in fact a bm1 mutant, with a sequence fully identical to the 5803Cbm1 sequence. The two new F7803bm1 (natural mutant) and Ev2210bm1 (transposon tagging Mutator investigations) both had a transposon insertion in the ZmCAD2 DNA, resulting in a truncated protein, even if the mRNA was produced. The biochemical characteristics of the Ev2210bm1 lignins corroborated the signature of CAD2 deficiency in plants, with the presence of aldehydes and atypical compounds and linkages. Considering lignin structure and content, CAD2 is likely a good target for the improvement of energy production based on maize and grass lignocellulosic biomass, including a greater susceptibility to environmentally friendly pretreatments, as it was shown in bmr sorghum. The interest in maize bm1 hybrids for cattle feeding also should be considered because there seem to be little or limited negative effects of CAD2 mutations on other agronomical traits

Clustering of Environmental Parameters Discriminates Drought and Heat Stress Bread Wheat Trials

International audienceWheat (Triticum aestivum L.) is the most widely cultivated crop worldwide and faces a wide range of stresses. To make effective crop improvement decisions, environmental characterization is of paramount importance. This study presents a new methodology for characterizing the environment that enables replacing the conventional arbitrary classification of the environment by a series of environmental covariates that capture and describe the stresses the plant encounters. Three CIMMYT bread wheat populations, combining complementary heat and drought adaptive traits, were grown over 3 yr in northwestern Mexico under limited irrigation, heat stress, and irrigated conditions. The network comprised 15 trials representing seven treatment x year combinations as experimental environments, referred to here as the "Environment". Environmental characterization was performed at the trial scale. Twelve stress thresholds related to eight environmental factors were combined to obtain 11 potential growth limiting factors. Thirty-three environmental covariates were obtained by calculating when these limiting factors occurred for each of three key-developmental-phases across all trials. Cluster analysis allowed grouping environmental covariates into six distinct clusters corresponding to six "environmental scenarios". One representative environmental covariate was extracted from each cluster and taken together explained more than 90% of the variance for yield in the Environment. Principal component analysis discriminated the seven experimental environments and identified its stress characteristics. We conclude that the method developed characterized the main stresses and their impact on average population performance, and the representative covariates efficiently replaced the Environment. As such, they will facilitate the dissection of genotype x environment interaction (GEI) for yield-related traits

Genetic and ecophysiological dissection of tolerance to drought and heat stress in bread wheat: from environmental characterization to QTL detection

National audienc

Environmental characterization and QTL detection to dissect wheat tolerance to drought and high temperature

International audienc

Selection and characterization of a winter wheat diversity panel

Selection and characterization of a winter wheat diversity panel. 7. Congress and Associate Symposiums of Breads of the future: genomics, genetics, breedin

Different mutations in the <em>ZmCAD2</em> gene underlie the maize brown-midrib1 (bm1) phenotype with similar effects on lignin characteristics and have potential interest for bioenergy production

International audienceThe maize ZmCAD2 gene has been fully sequenced in several normal and bm1 maize lines, highlighting a large diversity of mutations underlying the bm1 phenotype. Mutations in three bm1 lines (F2bm1, A619bm1, and 511Jbm1) were found corresponding to short InDels inducing premature stop codons and truncated proteins. In two lines (511Kbm1 and 5803Cbm1), mutations were limited to an only SNP or to a few SNP, modifying the catalytic sites, and likely inactivating the proteins. Results also established that the 5803Ibm7 mutant was in fact a bm1 mutant, with a sequence fully identical to the 5803Cbm1 sequence. The two new F7803bm1 (natural mutant) and Ev2210bm1 (transposon tagging Mutator investigations) both had a transposon insertion in the ZmCAD2 DNA, resulting in a truncated protein, even if the mRNA was produced. The biochemical characteristics of the Ev2210bm1 lignins corroborated the signature of CAD2 deficiency in plants, with the presence of aldehydes and atypical compounds and linkages. Considering lignin structure and content, CAD2 is likely a good target for the improvement of energy production based on maize and grass lignocellulosic biomass, including a greater susceptibility to environmentally friendly pretreatments, as it was shown in bmr sorghum. The interest in maize bm1 hybrids for cattle feeding also should be considered because there seem to be little or limited negative effects of CAD2 mutations on other agronomical traits

Different mutations in the <em>ZmCAD2</em> gene underlie the maize brown-midrib1 (bm1) phenotype with similar effects on lignin characteristics and have potential interest for bioenergy production

International audienceThe maize ZmCAD2 gene has been fully sequenced in several normal and bm1 maize lines, highlighting a large diversity of mutations underlying the bm1 phenotype. Mutations in three bm1 lines (F2bm1, A619bm1, and 511Jbm1) were found corresponding to short InDels inducing premature stop codons and truncated proteins. In two lines (511Kbm1 and 5803Cbm1), mutations were limited to an only SNP or to a few SNP, modifying the catalytic sites, and likely inactivating the proteins. Results also established that the 5803Ibm7 mutant was in fact a bm1 mutant, with a sequence fully identical to the 5803Cbm1 sequence. The two new F7803bm1 (natural mutant) and Ev2210bm1 (transposon tagging Mutator investigations) both had a transposon insertion in the ZmCAD2 DNA, resulting in a truncated protein, even if the mRNA was produced. The biochemical characteristics of the Ev2210bm1 lignins corroborated the signature of CAD2 deficiency in plants, with the presence of aldehydes and atypical compounds and linkages. Considering lignin structure and content, CAD2 is likely a good target for the improvement of energy production based on maize and grass lignocellulosic biomass, including a greater susceptibility to environmentally friendly pretreatments, as it was shown in bmr sorghum. The interest in maize bm1 hybrids for cattle feeding also should be considered because there seem to be little or limited negative effects of CAD2 mutations on other agronomical traits

5 Fagaceae Trees

Worldwide, there are more than 1,000 species belonging to the Fagaceae. All Fagaceae species are woody plants and are spread throughout the northern hemisphere, from the tropical to the boreal regions. The family comprises seven genera (Govaerts and Frodin 1998), and the number of species is extremely variable among genera: Castanea (12), Castanopsis (100 to 200), Chrysolepis (2), Fagus (11), Lithocarpus (300), Quercus (450 to 600), Trigonobalanus (3).Oaks (Quercus), chestnuts (Castanea), and beeches (Fagus) are widely used in forestry for wood products over the three continents (Asia, Europe, and America) and are important economic species. Consequently, they have received more attention in forest genetic research than other genera. In addition to their cultivation in forestry, chestnuts are also used for their fruit production and have been partially domesticated for that purpose. Castanopsis and Lithocarpus are important ecological components of the Asian flora and have recently been investigated for their biological diversity (Cannon and Manos 2003). The remaining genera comprise only a very few species and for the time being have been studied mainly in botany and taxonomy