Transcript profiles uncover temporal and stress-induced changes of metabolic pathways in germinating sugar beet seeds

<p>Abstract</p> <p>Background</p> <p>With a cultivation area of 1.75 Mio ha and sugar yield of 16.7 Mio tons in 2006, sugar beet is a crop of great economic importance in Europe. The productivity of sugar beet is determined significantly by seed vigour and field emergence potential; however, little is known about the molecular mechanisms underlying these traits. Both traits exhibit large variations within sugar beet germplasm that have been difficult to ascribe to either environmental or genetic causes. Among potential targets for trait improvement, an enhancement of stress tolerance is considered because of the high negative influence of environmental stresses on trait parameters. Extending our knowledge of genetic and molecular determinants of sugar beet germination, stress response and adaptation mechanisms would facilitate the detection of new targets for breeding crop with an enhanced field emergence potential.</p> <p>Results</p> <p>To gain insight into the sugar beet germination we initiated an analysis of gene expression in a well emerging sugar beet hybrid showing high germination potential under various environmental conditions. A total of 2,784 ESTs representing 2,251 'unigenes' was generated from dry mature and germinating seeds. Analysis of the temporal expression of these genes during germination under non-stress conditions uncovered drastic transcriptional changes accompanying a shift from quiescent to metabolically active stages of the plant life cycle. Assay of germination under stressful conditions revealed 157 genes showing significantly different expression patterns in response to stress. As deduced from transcriptome data, stress adaptation mechanisms included an alteration in reserve mobilization pathways, an accumulation of the osmoprotectant glycine betaine, late embryogenesis abundant proteins and detoxification enzymes. The observed transcriptional changes are supposed to be regulated by ABA-dependent signal transduction pathway.</p> <p>Conclusion</p> <p>This study provides an important step toward the understanding of main events and metabolic pathways during germination in sugar beet. The reported alterations of gene expression in response to stress shed light on sugar beet stress adaptation mechanisms. Some of the identified stress-responsive genes provide a new potential source for improvement of sugar beet stress tolerance during germination and field emergence.</p

Accelerating silphium domestication: An opportunity to develop new crop ideotypes and breeding strategies informed by multiple disciplines

Silphium perfoliatum L. (cup plant, silphie) and S. integrifolium Michx. (rosinweed, silflower) are in the same subfamily and tribe as sunflower (Helianthus annuus L.). Silphium perfoliatum has been grown in many countries as a forage or bioenergy crop with forage quality approaching that of alfalfa (Medicago sativa L.) and biomass yield close to maize (Zea mays L.) in some environments. Silphium integrifolium has large seeds with taste and oil quality similar to traditional oilseed sunflower. Silphium species are all long-lived, diploid perennials. Crops from this genus could improve the yield stability, soil, and biodiversity of agricultural landscapes because, in their wild state, they are deep rooted and support a wide diversity of pollinators. In contrast with premodern domestication, de novo domestication should be intentional and scientific. We have the luxury and obligation at this moment in history to expand the domestication ideotype from food and energy production to include (i) crop-driven ecosystem services important for sustainability, (ii) genetic diversity to enable breeding progress for centuries, (iii) natural adaptations and microbiome associations conferring resource use efficiency and stress tolerance, and (iv) improving domestication theory itself by monitoring genetic and ecophysiological changes from predomestication baselines. Achieving these goals rapidly will require the use of next-generation sequencing for marker development and an international, interdisciplinary team committed to collaboration and strategic planning.Fil: Van Tassel, David. Land Institute; Estados UnidosFil: Albrecht, Kenneth A.. University Of Wisconsin Madison;Fil: Bever, James D.. University of Kansas; Estados UnidosFil: Boe, Arvid A.. South Dakota State University; Estados UnidosFil: Brandvain, Yaniv. University of Minnesota; Estados UnidosFil: Crews, Timothy E.. Land Institute; Estados UnidosFil: Gansberger, Markus. Austrian Agency For Health And Food Safety; AustriaFil: Gerstberger, Pedro. University of Bayreuth; AlemaniaFil: González Paleo, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontológico Egidio Feruglio; ArgentinaFil: Hulke, Brent S.. United States Department of Agriculture. Agriculture Research Service; Estados UnidosFil: Kane, Nolan C.. University of Colorado; Estados UnidosFil: Johnson, Paul J.. Insect Biodiversity Laboratory; Estados UnidosFil: Pestsova, Elena G.. Heinrich Heine Universitat;Fil: Picasso Risso, Valentín D.. University of Wisconsin; Estados UnidosFil: Prasifka, Jarrad R.. United States Department of Agriculture. Agriculture Research Service; Estados UnidosFil: Ravetta, Damián Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontológico Egidio Feruglio; ArgentinaFil: Schlautman, Brandon. Land Institute; Estados UnidosFil: Sheaffer, Craig C.. University of Minnesota; Estados UnidosFil: Smith, Kevin P.. University of Minnesota; Estados UnidosFil: Speranza, Pablo R.. Universidad de la República; Urugua