Biofortification of common bean for higher iron concentration

Common bean (Phaseolus vulgaris L.) is a staple food of smallholder farmers and poor urban consumers in Latin America and eastern-southern Africa among whom iron deficiency is frequent. Bean was domesticated in Mexico and the southern Andes, creating two distinct gene pools. Evaluation of a core collection of 1,441 entries revealed average concentrations of 55 mg kg−1 iron. A breeding target was set at 44 mg kg−1 iron above the level in a local check variety, while 50% of goal or a 22 mg kg−1 advantage was accepted as “biofortified.” In a bioefficacy trial among college-age women in Rwanda, high iron beans improved iron status and enhanced cognitive ability, brain function, and work efficiency. However, breeding progress has been slow, likely due in part to homeostatic mechanisms whereby organisms moderate iron and zinc uptake. This phenomenon may represent resistance to increasing concentration of these elements. Crosses between gene pools may “jumble” genes for homeostasis and permit high levels. A second breeding strategy is the use of sister species that evolved in iron-poor environments and that could be more receptive to iron uptake. Future breeding may also increase attention on improving bioavailability through mechanisms such as non-or-slow darkening grain or low phytate mutants. Changing dietary patterns in developed countries could increase iron deficiency and create demand for iron biofortified beans

Editorial Board

This nursery was organized in response to the need for improving adaptation and obtaining genetic information on the resistance or reaction to the different stress environments (biotic and abiotic) to which beans are subjected in production areas. Results are given for the best black- and red-seeded lines of the 1987 VIDAC, covering characteristics such as 100 seeds, days to flowering and physiological maturity, wt. of and response to diseases such as rust (Uromyces phaseoli), bacterioses (Xanthomonas phaseoli), BGMV, and web blight (Thanatephorus cucumeris). The yield potential and genetic adaptation of the best materials over different sites are also analyzed. Information on these national and regional trials should be collected in an efficient regional information and documentation center. (CIAT)Este vivero se organizo con base en la necesidad de conseguir una mejor adaptacion e informacion genetica sobre la resistencia o la reaccion a los diferentes ambientes de estres (bioticos o abioticos) a los cuales se somete el frijol en las areas de produccion. Se presentan los resultados de las mejores lineas de semilla negra y semilla roja de los VIDAC de 1987, para las caracteristicas de peso de 100 semillas, dias a floracion y a madurez fisiologica, y respuesta a enfermedades como roya (Uromyces phaseoli), bacteriosis (Xanthomonas phaseoli), BGMV y mustia hilachosa (Thanathephorus cucumeris). Tambien, se examinan el potencial de rendimiento y la adaptacion genetica de los mejores materiales en diferentes sitios. Es necesario reunir gran cantidad de informacion sobre estos ensayos nacionales y regionales en un centro de informacion y documentacion regional eficiente. (CIAT

Type I cAMP-Dependent Protein Kinase Delays Apoptosis in Human Neutrophils at a Site Upstream of Caspase-3

Current data suggest that apoptosis controls neutrophil numbers in tissues. We analyzed roles for and the sites of action for the cAMP-dependent protein kinases (cAPKs) in apoptosis induced in human neutrophils by in vitro storage, cycloheximide (CHX) exposure, and anti-Fas exposure. Treatment with 8-chlorophenylthio-cAMP (8-CPT-cAMP) prolonged the time required for 50% of the cells to exhibit apoptotic morphology (t 50) from 16.3 to 41.8 h (in vitro culture), from 2.4 to 7.8 h (CHX), and from 4.8 to 6.5 h (anti-Fas). CHX ± 8-CPT-cAMP did not significantly alter resting intracellular calcium levels and H-89, a selective inhibitor of cAPK, had no effect on apoptosis in the absence of the analogue. In contrast, site-selective cAMP analogues that specifically activated the type I cAPK, but not type II cAPK, synergistically attenuated apoptosis. Exposure to 8-CPT-cAMP delayed, in parallel, the activity of caspase-3 (CPP-32β), whereas mitogen-activated protein kinase kinase (MAPKK) inhibitor, PD98059, had no effect on CHX-induced apoptosis ± 8-CPT-cAMP. Together these results indicate that type I cAPK activation is necessary and sufficient to mediate cAMP-induced delay in human neutrophil apoptosis induced by several mechanisms and suggest that one of the major sites of cAPK action is upstream of caspase-3 (CPP-32β) activation