Can plant biotechnology help in solving our food and energy shortage in the future?

Accumulation of starch in duckweeds (Lemnaceae), potential energy plants

Starch can accumulate in both actively growing vegetative fronds and over-wintering propagules, or turions of duckweeds, small floating aquatic plants belonging to the family of the Lemnaceae. The starch synthesizing potential of 36 duckweed species varies enormously, and the starch contents actually occurring in the duckweed tissues are determined by growth conditions, various types of stress and the action of growth regulators. The present review examines the effects of phytohormones and growth retardants, heavy metals, nutrient deficiency and salinity on the accumulation of starch in duckweeds with a view to obtaining high yields of starch as a feedstock for biofuel production. Biotechnological approaches to degrading duckweed starch to its component sugars and the fermentation of these sugars to bio-alcohols are also discussed.

Compositional and proteomic analyses of genetically modified broccoli (Brassica oleracea var. italica) harboring an agrobacterial gene

Previously, we showed improved shelf life for agrobacterial isopentenyltransferase (ipt) transgenic broccoli (Brassica oleracea var. italica), with yield comparable to commercial varieties, because of the protection mechanism offered by molecular chaperones and stress-related proteins. Here, we used proximate analysis to examine macronutrients, chemical and mineral constituents as well as anti-nutrient and protein changes of ipt-transgenic broccoli and corresponding controls. We also preliminarily assessed safety in mice. Most aspects were comparable between ipt-transgenic broccoli and controls, except for a significant increase in carbohydrate level and a decrease in magnesium content in ipt-transgenic lines 101, 102 and 103, as compared with non-transgenic controls. In addition, the anti-nutrient glucosinolate content was increased and crude fat content decreased in inbred control 104 and transgenic lines as compared with the parental control, "Green King". Gel-based proteomics detected more than 50 protein spots specifically found in ipt-transgenic broccoli at harvest and after cooking; one-third of these proteins showed homology to potential allergens that also play an important role in plant defense against stresses and senescence. Mice fed levels of ipt-transgenic broccoli mimicking the 120 g/day of broccoli eaten by a 60-kg human adult showed normal growth and immune function. In conclusion, the compositional and proteomic changes attributed to the transgenic ipt gene did not affect the growth and immune response of mice under the feeding regimes examined.

The Arabidopsis Information Resource (TAIR): improved gene annotation and new tools

The Arabidopsis Information Resource (TAIR, http://arabidopsis.org) is a genome database for Arabidopsis thaliana, an important reference organism for many fundamental aspects of biology as well as basic and applied plant biology research. TAIR serves as a central access point for Arabidopsis data, annotates gene function and expression patterns using controlled vocabulary terms, and maintains and updates the A. thaliana genome assembly and annotation. TAIR also provides researchers with an extensive set of visualization and analysis tools. Recent developments include several new genome releases (TAIR8, TAIR9 and TAIR10) in which the A. thaliana assembly was updated, pseudogenes and transposon genes were re-annotated, and new data from proteomics and next generation transcriptome sequencing were incorporated into gene models and splice variants. Other highlights include progress on functional annotation of the genome and the release of several new tools including Textpresso for Arabidopsis which provides the capability to carry out full text searches on a large body of research literature.