Identification of duplicated and stress-inducible Aox2b gene co-expressed with Aox1 in species of the Medicago genus reveals a regulation linked to gene rearrangement in leguminous genomes

In flowering plants, alternative oxidase (Aox) is encoded by 3-5 genes distributed in 2 subfamilies (Aox1 and Aox2). In several species only Aox1 is reported as a stress-responsive gene, but in the leguminous Vigna unguiculata Aox2b is also induced by stress. In this work we investigated the Aox genes from two leguminous species of the Medicago genus (Medicago sativa and Medicago truncatula) which present one Aox1, one Aox2a and an Aox2b duplication (named here Aox2b1 and Aox2b2). Expression analyses by semi-quantitative RT-PCR in M. sativa revealed that Aox1, Aox2b1 and Aox2b2 transcripts increased during seed germination. Similar analyses in leaves and roots under different treatments (SA, PEG, H2O2 and cysteine) revealed that these genes are also induced by stress, but with peculiar spatio-temporal differences. Aox1 and Aox2b1 showed basal levels of expression under control conditions and were induced by stress in leaves and roots. Aox2b2 presented a dual behavior, i.e., it was expressed only under stress conditions in leaves, and showed basal expression levels in roots that were induced by stress. Moreover, Aox2a was expressed at higher levels in leaves and during seed germination than in roots and appeared to be not responsive to stress. The Aox expression profiles obtained from a M. truncatula microarray dataset also revealed a stress-induced co-expression of Aox1, Aox2b1 and Aox2b2 in leaves and roots. These results reinforce the stress-inducible co-expression of Aox1/Aox2b in some leguminous plants. Comparative genomic analysis indicates that this regulation is linked to Aox1/Aox2b proximity in the genome as a result of the gene rearrangement that occurred in some leguminous plants during evolution. The differential expression of Aox2b1/2b2 suggests that a second gene has been originated by recent gene duplication with neofunctionalization. © 2013 Elsevier GmbH. All rights reserved.

Sistemas de manejo e efeito residual do potássio na produtividade e nutrição do feijão-caupi

Cowpea [Vigna unguiculata (L) Walp] have great social and economic importance for the Para State. It grows well in areas with low precipitation and two crop cycles can be obtained annually. This study aimed to assess the effect of the residual fertilization from a previous culture (Sorghum bicolor L. Moench) and crop systems on cowpea yield and macronutrient concentration on leaves of three cowpea cultivars (BRSMilênio, BRS-Urubuquara e BRS-Guariba). The study was conducted at the UFRA. The treatments were two crop systems (minimum tillage and conventional), four levels of potassium (50, 100, 200 e 300 kg de KCl ha-1 applied to a previous sorghum culture) and the three cowpea cultivars. Treatments were organized as a three (4 x 2 x 3) factor experiment on a randomized complete block design. The soil was a yellow latosol. In each experiment plot five plants were selected to determine shoot dry matter and foliar nutrient concentration. Grain yield was determined after harvesting all plants on the experiment plot. The residual KCl fertilization affected foliar nutrient content, but did not affect shoot dry mass or yield of grain. Yield was higher in the minimum tillage system. Highest yield (1590 kg ha-1) was recorded int the cv. 'Guariba' when 100 kg of KCl ha-1 had been used in the previous crop. The highest content of leaf N and K was found in cowpea under minimum tillage system. The amount of P and Mg were higher in the conventional system whereas the amount of Ca did not change.

Microbiota do solo em sistemas de produção de grãos no plantio direto

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Milho e feijão-caupi cultivados em faixas na safrinha

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Vicilinas de leguminosas e seus efeitos no metabolismo lipídico de ratos dislipidêmicos

Pós-graduação em Alimentos e Nutrição - FCFAR

Caracterização de isolados e reação de Capsicum spp. ao Cucumber mosaic virus (CMV)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos de genótipos de feijão caupi e de espécies botânicas em diferentes formulações sobre Callosobruchus maculatus (FABR.)

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Desempenho agronômico de feijão‑caupi e milho semeados em faixas na safrinha

O objetivo deste trabalho foi avaliar o desempenho agronômico de cultivares de feijão‑caupi e de milho, em monocultivo e em cultivo consorciado em faixas, na safrinha. Foram realizados experimentos, em Dourados, MS (2009 e 2010), e em Botucatu, SP (2010). Utilizou-se o delineamento experimental de blocos ao acaso, com parcelas subdivididas e quatro repetições. As parcelas com feijão‑caupi foram constituídas por três sistemas de cultivo (em faixas com variedade ou híbrido de milho, além do cultivo solteiro) e as subparcelas, por três cultivares de feijão‑caupi (BRS Guariba, BRS Novaera e BRS Xiquexique). As parcelas com milho foram constituídas por duas cultivares de milho (variedade BR 473 e híbrido BRS 1030 ou BRS 1010), e as subparcelas, por quatro sistemas de cultivo (em faixas com as três cultivares de feijão‑caupi e solteiro). O sistema de consórcio em faixas consistiu de quatro fileiras de feijão‑caupi com quatro fileiras de milho. O consórcio proporcionou um uso mais eficiente da terra. As cultivares de feijão‑caupi apresentaram desempenho produtivo semelhante entre si, quando cultivadas em faixas com o milho. O híbrido de milho é mais produtivo que a variedade, tanto no cultivo solteiro quanto no consorciado.

Characterization of cowpea genotype resistance to Callosobruchus maculatus

The objective of this work was to characterize the resistance of 50 cowpea (Vigna unguiculata) genotypes to Callosobruchus maculatus. A completely randomized design with five replicates per treatment (genotype) was used. No-choice tests were performed using the 50 cowpea genotypes to evaluate the preference for oviposition and the development of the weevil. The genotypes IT85 F-2687, MN05-841 B-49, MNC99-508-1, MNC99-510-8, TVu 1593, Canapuzinho-1-2, and Sanzi Sambili show non-preference-type resistance (oviposition and feeding). IT81 D-1045 Ereto and IT81 D-1045 Enramador exhibit antibiosis against C. maculatus and descend from resistant genitors, which grants them potential to be used in future crossings to obtain cowpea varieties with higher levels of resistance.

Heavy metals and yield of cowpea cultivated under composted tannery sludge amendment

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Characterization of antibiosis to the silverleaf whitefly Bemisia tabaci biotype B (Hemiptera: Aleyrodidae) in cowpea entries

The silverleaf whitefly, Bemisia tabaci (Gennadius) biotype B (Hemiptera: Aleyrodidae), is considered one of the most important pests of cowpea (Vigna unguiculata L. Walp.), limiting the productivity of this crop worldwide. Chemical control is still the main strategy for the management of populations of this insect. However, due to the harmful effects of pesticides on the environment and to humans, less injurious alternatives have been investigated. Along this line, the use of resistant genotypes can be a valuable tool for the control of the silverleaf whitefly. In this paper, we investigate some biological aspects of B. tabaci biotype B confined on 14 genotypes of cowpea. We evaluated the incubation period, egg viability, duration of nymphal stages, total duration of the juvenile phase, instar mortality and total mortality of the immature stage. The genotype MNC 99-541 F21 exhibited antibiosis against the whitefly, prolonging the lifecycle of the insect. The genotypes Canapu, BRS-Urubuquara and TE97-304 G-4 also exhibited antibiosis, causing high nymphal mortality. These results may help in breeding programmes to develop cowpea lines with resistance to B. tabaci biotype B.

Growth and nodulation of cowpea after 5 years of consecutive composted tannery sludge amendment

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Épocas de semeadura e populações de plantas para Cultivares de feijão-caupi no outono-inverno em Botucatu-SP

Pós-graduação em Agronomia (Agricultura) - FCA

Chromium in soil organic matter and cowpea after four consecutive annual applications of composted tannery sludge

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Hypocholesterolaemic effect of rat-administered oral doses of the isolated 7S globulins from cowpeas and adzuki beans

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)