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Abstract: [SALY, SENEGAL] A pest-resistant version of the black-eyed pea, a subspecies of the cowpea, is on track for commercial introduction, promising higher yields and claimed savings of up to US$1 billion on a crop that has found new popularity among African smallholders.

The cowpea, actually a bean, is rich in protein and is an important crop for both tackling malnutrition and adapting to climate change as it tolerates hot, dry conditions.

But infestation by the Maruca vitrata pod borer has cut the value of crops by up to US$300 million for smallholders in Africa, who produce nearly 5.2 million tonnes of the bean. The continent currently accounts for about 70 per cent of global production.

Now, scientists at the Institute for Agricultural Research (IAR) at Ahmadu Bello University, Nigeria, in collaboration with other institutes including the African Agricultural Technology Foundation, Kenya, have engineered an insect-resistant Bt (Bacillus thuringiensis) cowpea that they say could be on shelves in six years.

The cowpea — an ancient African crop — has been making a comeback in recent years, with increased yields seen across Africa, delegates heard this week (27 September–1 October) at the 5th World Cowpea Conference in Dakar, Senegal.

"The cowpea is emerging as one of the most important food legumes because of its early maturity and its fit as a niche crop in multiple cropping systems," said B. B. Singh, an international cowpea breeder and visiting scientist at Texas A&M University in the United States.

He noted that there has already been a six-fold increase in world cowpea production in the last few decades, a "quiet revolution that is greater in magnitude than that of cereals and all other pulses".

Christian Fatokun, a cowpea breeder at the International Institute of Tropical Agriculture (IITA), Nigeria, said that, as the crop is grown on a small scale by ill-resourced farmers, no commercial seed company will service this sector. And, because the cowpea is self-pollinating, companies also have little incentive to supply seeds.

The Bt cowpea will raise the status of the bean, claimed its developers. It could also generate up to US$1 billion by 2020 for farmers.

"Up until now, nobody in the scientific world was able to introduce resistance to this insect into cowpea," said Mohammad Faguji Ishiyaku, principal investigator of the Bt cowpea project and a researcher at the IAR. "Our research will mean increased income by using less insecticide and increased productivity for areas growing cowpeas. Farmers will also have reduced exposure to harmful chemicals."

IITA agricultural economist, Ousmane Coulibaly, said surveys on cowpea in Nigeria, Benin, Mali and Burkina Faso have found that farmers are using a lot of expensive and sometimes harmful pesticides. In Nigeria — the largest producer and consumer of cowpea in Africa — net gains from not using pesticides could be about $500 million, he said.

URL: http://www.scidev.net/fr/agriculture-and-environment/news/le-ni-b-bt-pourrait-rapporter-jusqu-us-1milliard-aux-petits-agriculteurs.html XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Author: Bustos Regla, Gabriel Castrillo, Francisco Linhares, María Isabel Puga, Vicente Rubio, Julian PérezPérez, Roberto Solano, Antonio Leyva, Javier Paz-Ares, Year: 2010 Title: * A Central Regulatory System Largely Controls Transcriptional Activation and Repression Responses to Phosphate Starvation in Arabidopsis.

Journal: PLoS Genet 6(9): e1001102. doi:10.1371/journal.pgen.1001102 Label: ReEn MacroEl Abstract: Plants respond to different stresses by inducing or repressing transcription of partially overlapping sets of genes. In Arabidopsis, the PHR1 transcription factor (TF) has an important role in the control of phosphate (Pi) starvation stress responses. Using transcriptomic analysis of Pi starvation in phr1, and phr1 phr1-like (phl1) mutants and in wild type plants, we show that PHR1 in conjunction with PHL1 controls most transcriptional activation and repression responses to phosphate starvation, regardless of the Pi starvation specificity of these responses. Induced genes are enriched in PHR1 binding sequences (P1BS) in their promoters, whereas repressed genes do not show such enrichment, suggesting that PHR1(-like) control of transcriptional repression responses is indirect. In agreement with this, transcriptomic analysis of a transgenic plant expressing PHR1 fused to the hormone ligand domain of the glucocorticoid receptor showed that PHR1 direct targets (i.e., displaying altered expression after GR:PHR1 activation by dexamethasone in the presence of cycloheximide) corresponded largely to Pi starvation-induced genes that are highly enriched in P1BS. A minimal promoter