Drought-Induced Effects and Recovery of Nitrate Assimilation and Nodule Activity in Cowpea Plants Inoculated With Bradyrhizobium Spp. Under Moderate Nitrate Level

Silveira, Joaquim Albenísio Gomes da; Costa, Roberto Cezar Lobo da; Oliveira, José T.A.

doi:10.1590/s1517-83822001000300005

Cited by 51 publications

(30 citation statements)

References 28 publications

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“…The seedlings were reinoculated four days later. The plants were irrigated daily by a capillary sub-irrigation system (Leonard jars modified) with 800 cm 3 of a N-free nutrient solution composed of (mol m 3 ): K 2 SO 4 =2.0; CaCl 2 =3.0; K 2 HPO 4 =1.0; MgSO 4 =1.0 and micronutrients as previously described (Silveira et al, 2001). The nutrient solution was changed each four days and the pH maintained at 6.0 ± 0.5 with addition of 0.1 mol m -3 HCl or NaOH.…”

Section: Methodsmentioning

confidence: 99%

“…Thus, it is very important the comprehension of the mechanisms involved in the recovery of the plant associated with the nodule activity for N 2 fixation under short periods of drought-stress followed by rehydration, an environmental condition that is recurrent in the semi-arid tropical regions, where cowpea is largely cultivated (Figueiredo et al, 1999a). Recently we demonstrated that cowpea was more sensitive to drought-stress in terms of the nodule growth and nitrogenase activity than in relation to activities of nitrogen assimilation enzymes (Figueiredo et al, 1999b;Silveira et al, 2001). In this study nodulated cowpea plants were exposed to a progressive drought-stress followed by rewatering in order to establish mechanisms related to the nodule sensitivity to N 2 fixation.…”

Section: Introductionmentioning

confidence: 94%

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N-compound accumulation and carbohydrate shortage on N2 fixation in drought-stressed and rewatered cowpea plants

et al. 2003

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In this study nodulated cowpea plants were exposed to a progressive drought-stress followed by rewatering in order to establish mechanisms related to the nodule sensitivity to N 2 fixation. Water stress caused a prominent decrease in the dry matter of leaf and nodule in contrast to the root growth that was stimulated. The drought-stressed plants showed a great decline in the ureide concentration of xylem sap whilst the concentration of the nodule leghaemoglobin decreased slightly. The stressed-nodules had significant accumulation of soluble carbohydrates in parallel to intense increase in the concentration of ureide, total amino acid and proline. After two days rewatering, the leaf growth showed a significant enhancement whereas in nodules a poor recovery was observed. In addition, the nodule N 2 fixation capacity did not improve after rehydration whereas the sap ureide experienced only a slight recovery and surprisingly the content of nodule soluble protein continued to drop. In contrast, a significant recovery in the nodule leghaemoglobin content was observed. Rewatering greatly induced depletion of both sucrose and total soluble sugar contents of nodules that were associated to a great decrease in the concentration of ureide, proline and amino acids, especially in leaves. Conversely the poor recovery of cowpea nodules after rehydration was apparently related to a carbohydrate shortage.Key words: leghaemoglobin, ureide, symbiose, water stress, Vigna unguiculata. Resumen Acumulación de componentes nitrogenados y reducción de carbohidratos en la fijación de nitrógeno de plantas de Vigna unguiculata (L.) Walp sometidas a estrés hídrico y rehidratadasA fin de establecer los mecanismos relacionados con la capacidad de los nódulos para fijar nitrógeno atmosférico, se expusieron plantas de Vigna unguiculata (L.) Walp noduladas a un estrés progresivo de sequía seguido de rehidratación. La sequía produjo una importante disminución en la materia seca de las hojas y de los nódulos, y en cambio estimuló el crecimiento de las raíces; por otro lado, hubo una gran disminución en la concentración de ureidos de la savia del xilema. Los nódulos sometidos a estrés presentaron una acumulación significativa de carbohidratos solubles, junto con un intenso aumento de la concentración de ureidos, aminoácidos totales y prolina, disminuyendo levemente la concentración de leghemoglobina. Tras dos días de rehidratación, el crecimiento de las hojas aumentó significativamente, pero tanto los ureidos de la savia como los nódulos sólo se recuperaron de forma leve, y no aumentó su capacidad de fijación de N 2 . Además, sorprendentemente, el contenido de proteínas solubles de los nódulos siguió disminuyendo, aunque el contenido de leghemoglobina se recuperó significativamente. Una rehidratación intensa indujo reducción tanto en el contenido de sacarosa como de azúcares solubles totales de los nódulos, junto con una gran disminución en la concentración de ureidos, prolina y aminoácidos, especialmente en las hojas. La pobre recuperación ...

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 94%

N-compound accumulation and carbohydrate shortage on N2 fixation in drought-stressed and rewatered cowpea plants

et al. 2003

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“…No tocante às plantas de cobertura, com exceção da vegetação espontânea, o número de nódulos do caupi nos tratamentos com adubo foi inferior ao encontrado para as plantas inoculadas (Figura 1), indicando provável efeito negativo do N sobre a nodulação, conforme também encontrado por diversos autores (Lopes et al, 1996;Silveira et al, 2001;Silva, 2006), embora outros autores não tenham observado efeitos similares (Stamford et al, 1995;Kahn & Schroeder, 1999).…”

Section: Resultsunclassified

Nodulação e produção do caupi (Vigna unguiculata L. Walp) sob efeito de plantas de cobertura e inoculação

Nascimento

Lira

Stamford

et al. 2008

Rev. Bras. Ciênc. Solo

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RESUMOUm experimento de campo foi realizado no município de Crato -Ceará para estudar como a planta de cobertura afeta a nodulação e produtividade de caupi (Vigna unguiculata (L.) Walp), submetido a diferentes inoculações. Empregou-se o delineamento em blocos casualizados, no esquema em parcelas subsubdivididas, com quatro repetições. Os tratamentos consistiram de plantas de cobertura, formando a parcela principal; inoculação, como subparcela; e amostragens quinzenais, como subsubparcela. As plantas de cobertura foram: milhetoPennisetum americanum; mucuna-preta -Stizolobium aterrimum ou vegetação espontânea, enquanto as fontes de N foram: sem inoculação; sem inoculação + 50 kg ha -1 de N na forma de uréia; inoculação com estirpes rizobianas (Bradyrhizobium sp.) recomendadas pela RELARE -BR 3301 + BR 3302; ou pela UFRPE -NFB 6156 + NFB 700. Foi utilizada a cultivar Patativa de caupi, recomendada para a região. A partir de sete dias após a emergência e até a maturidade final da cultura, foram realizadas amostras quinzenais, colhendo-se duas plantas, por subparcela para determinação do número de nódulos, matéria seca de nódulos e matéria seca da parte aérea. A partir dos 60 dias após emergência, foram realizadas colheitas semanais da área útil da subparcela, para determinação da produtividade de grãos. A mucuna aumentou a nodulação do caupi não-inoculado. A inoculação do caupi com estirpes recomendadas, ou o aumento da

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“…Intra-species variation in biological nitrogen fixation has been observed throughout the legume family [30,87] including within Glycine max (soybean) [88], Lablab purpureus [89], Vicia faba (faba bean) [90,91], Trifolium alexandrinum (bersem clover) [36,[92][93][94], Phaseolus vulgaris (common bean) [95,96], Pisum sativum (green pea) [97], V. unguiculata (cowpea) [98], and Vigna aconitifolia (mothbean) [93]. Optimizing biological nitrogen fixation involves the selection of not only the best legume genotype but also selecting the most optimal legume and rhizobia combination [30].…”

Section: Dry Season Wild Plants Can Be Optimized As Cover Crops Throumentioning

confidence: 99%

Mitigating dry season food insecurity in the subtropics by prospecting drought-tolerant, nitrogen-fixing weeds

Small

Raizada

2017

Agric & Food Secur

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Subtropical regions experience an extended dry season, which inhibits the growth of most crops, and as a result there is seasonal scarcity of food and fodder. Globally, almost 600 million smallholders and landless laborers experience hunger in the dry season. This situation is expected to worsen, as water shortages are expected to impact up to twothirds of humanity between 2010 and 2050. A second challenge is that 45% of the world's agricultural land is sloped and vulnerable to intense surface runoff during the transition from the dry to rainy season (e.g., monsoon). Erosion, along with nutrient mining, contributes to a net loss of soil fertility. Drought-tolerant legumes can mitigate these challenges. Legumes form symbiotic relationships with microbes that can sequester atmospheric nitrogen gas as ammonia, a process termed biological nitrogen fixation (BNF). As a result of BNF, legumes are rich in nitrogen, which is a building block of edible protein and organic nitrogen fertilizer to replenish soils. Leguminous cover crops can be used as food/feed, and as a tool to reduce the need for synthetic fertilizers, prevent erosion, and suppress undesired weeds that grow on bare, dry soil that otherwise cause female drudgery. Unfortunately, cover cropping is not a traditional practice in most subtropical regions and BNF is inhibited by drought (dry season). Subsistence farmers around the world would benefit from nutritious and drought-tolerant cover crops that can sustain nitrogen fixation in the dry season. Here, we propose that neglected crops in addition to native and naturalized plants that persist in the dry season, often considered to be weeds, may be utilized for the development of new cover crops. A detailed framework is presented for the identification, characterization, and selection of such species. As a case study, the framework was applied to the mid-hills of Nepal. A literature review, stakeholder interviews, and field site visits with farmers informed the selection of 78 candidate dry season leguminous cover crop species. It is hoped that this innovative approach will serve as a model to help alleviate food/feed shortages and improve the livelihoods of subsistence farmers in the global subtropics.

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Drought-Induced Effects and Recovery of Nitrate Assimilation and Nodule Activity in Cowpea Plants Inoculated With Bradyrhizobium Spp. Under Moderate Nitrate Level

Cited by 51 publications

References 28 publications

N-compound accumulation and carbohydrate shortage on N2 fixation in drought-stressed and rewatered cowpea plants

N-compound accumulation and carbohydrate shortage on N2 fixation in drought-stressed and rewatered cowpea plants

Nodulação e produção do caupi (Vigna unguiculata L. Walp) sob efeito de plantas de cobertura e inoculação

Mitigating dry season food insecurity in the subtropics by prospecting drought-tolerant, nitrogen-fixing weeds

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