A multicystatin is induced by drought-stress in cowpea (Vigna unguiculata(L.) Walp.) leaves

Cowpea (Vigna unguiculata (L.) Walp.) is an important commodity in West Africa. Its seeds are a valuable source of protein, vitamins, and income for humans. However, cowpea cultivation in Benin faces climatic constraints such as water stress caused by a prolonged absence of rain during the rainy season. Thus, this work aims at selecting cowpea varieties that can be cultivated in times of drought without compromising their yields and yield components. Twenty cowpea varieties were used, including 17 improved cultivars and 3 landraces. The experiment was conducted at the International Institute of Tropical Agriculture in Benin and laid at a split-plot design with four replicates. Each genotype was exposed to three water treatments: fully irrigated control, vegetative stress (when plants were 23 days old, drought stress was imposed for 30 days), and reproductive stress (once the first flowers were observed, water stress was imposed for 30 days). The results showed that photochemical yield, chlorophyll content, and relative water content were reduced under water deficit at the vegetative and reproductive stages. But there were no significant differences in proline content among cowpea varieties. Agronomic traits such as number of days to flowering, number of pods, yield per plant, the weight of 100 seeds, and harvest time showed significant differences under water stress. Overall, the landraces and cultivars including Kpodjiguegue, KVX 61-1, and IT 06-K-242-3 were the most tolerant to drought stress at the vegetative and reproductive stages and could potentially be used in breeding programs to improve drought tolerance of cowpeas.

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NITROGENASE ACTIVITY, PHOTOSYNTHESIS AND TOTAL NONSTRUCTURAL CARBOHYDRATES IN COWPEA DURING AND AFTER DROUGHT STRESS

Canadian Journal of Plant Science ◽

10.4141/cjps90-123 ◽

1990 ◽

Vol 70 (4) ◽

pp. 1005-1012 ◽

Cited By ~ 5

Author(s):

S. PARARAJASINGHAM ◽

D. P. KNIEVEL

Keyword(s):

Drought Stress ◽

Stomatal Conductance ◽

Vigna Unguiculata ◽

Nitrogenase Activity ◽

Net Photosynthesis ◽

Dry Weight ◽

Plant Parts ◽

Total Nonstructural Carbohydrates ◽

Nonstructural Carbohydrate ◽

And Control

Greenhouse experiments were conducted to determine whether depressed nitrogenase activity (NA) of cowpea (Vigna unguiculata (L.) Walp.) nodules during drought stress is associated with altered carbohydrate supply to the nodules. Nitrogenase activity of the nodules, midday abaxial stomatal conductance, leaf net photosynthesis and mg total nonstructural carbohydrate (TNC) g−1 dry weight of several plant parts were measured in cowpea subjected to and recovering from drought stress periods of 0, 4 and 8 days. In addition, cowpea plants were shaded or partially defoliated (75% leaf removal) to limit carbohydrate supply to the nodules of well-watered plants. Stomatal conductance, leaf net photosynthesis and nodule NA declined 60, 62 and 90%, respectively, within 4 d of withholding water. After 8 d of drought stress, leaf net photosynthesis and nodule NA were near zero. Stomatal conductance and leaf net photosynthesis returned to the level of unstressed plants within 24 h following rewatering while recovery of NA was delayed. Shading and defoliation of cowpea plants under well watered conditions decreased NA 62 and 44%, respectively. TNC concentrations of leaves, petioles, stems, roots and nodules did not differ appreciably between drought stressed and control plants. In contrast, TNC concentrations of shoot plant parts from shaded or defoliated plants declined significantly compared to controls and nodule TNC concentrations declined in shaded plants. The decline in NA by cowpea nodules during drought stress did not appear to be directly associated with carbohydrate supply to the nodules, but rather the result of a new equilibrium attained with overall limited plant growth under the stress.Key words: Vigna unguiculata (L.) Walp., nitrogenase activity, drought stress recovery, assimilate stress, shading, defoliation, total nonstructural carbohydrate

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A patatin-like protein with galactolipase activity is induced by drought stress in Vigna unguiculata leaves

Biochemical Society Transactions ◽

10.1042/bst0280779 ◽

2000 ◽

Vol 28 (6) ◽

pp. 779-781 ◽

Cited By ~ 9

Author(s):

A. R. Matos ◽

A. d'Arcy-Lameta ◽

M. França ◽

Y. Zuily-Fodil ◽

A. T. Pham-Thi

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Recombinant Protein ◽

Fusion Protein ◽

Vigna Unguiculata ◽

Northern Blot ◽

Culture Medium ◽

Lipolytic Activity ◽

Major Protein ◽

Baculovirus System

This paper reports the cloning of a cDNA (Vupat 1) expressed in Vigna unguiculata leaves coding for a protein with 48% sequence homology to patatin, the major protein from potato tuber which has lipolytic acylhydrolase activity. Two cultivars differing in drought tolerance were ex-amined in Northern-blot analyses. Expression of Vupat 1 is stimulated by drought stress, especially in the drought-sensitive cultivar. Vupat 1 was expressed in the baculovirus system as a fusion protein secreted in the culture medium. The recombinant protein displays lipolytic activity towards monogalactosyldiacylglycerol, digalactosyldiacylglycerol and sulphoquinovosyldiacylglycerols.

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Mapping QTL for drought stress-induced premature senescence and maturity in cowpea [Vigna unguiculata (L.) Walp.]

Theoretical and Applied Genetics ◽

10.1007/s00122-008-0944-7 ◽

2009 ◽

Vol 118 (5) ◽

pp. 849-863 ◽

Cited By ~ 60

Author(s):

Wellington Muchero ◽

Jeffrey D. Ehlers ◽

Timothy J. Close ◽

Philip A. Roberts

Keyword(s):

Drought Stress ◽

Vigna Unguiculata ◽

Premature Senescence ◽

Mapping Qtl ◽

Stress Induced Premature Senescence

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Enzymatic degradation of polar lipids in Vigna unguiculata leaves and influence of drought stress

Physiologia Plantarum ◽

10.1034/j.1399-3054.1998.1040409.x ◽

1998 ◽

Vol 104 (4) ◽

pp. 577-586 ◽

Cited By ~ 45

Author(s):

Y. Sahsah ◽

P. Campos ◽

M. Gareil ◽

Y. Zuily-Fodil ◽

A. T. Pham-Thi

Keyword(s):

Drought Stress ◽

Vigna Unguiculata ◽

Enzymatic Degradation ◽

Polar Lipids

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NITROGENASE ACTIVITY OF COWPEA (Vigna unguiculata (L.) Walp.) DURING AND AFTER DROUGHT STRESS

Canadian Journal of Plant Science ◽

10.4141/cjps90-018 ◽

1990 ◽

Vol 70 (1) ◽

pp. 163-171 ◽

Cited By ~ 5

Author(s):

S. PARARAJASINGHAM ◽

D. P. KNIEVEL

Keyword(s):

Drought Stress ◽

Stomatal Conductance ◽

Water Potential ◽

Vigna Unguiculata ◽

Nitrogenase Activity ◽

Root Nodules ◽

Experimental Period ◽

Stress Recovery ◽

Subsequent Recovery ◽

Per Se

Greenhouse experiments were conducted with the objectives (1) to investigate the nitrogenase activity (NA) of cowpea (Vigna unguiculata (L.) Walp.) root nodules during the development of and subsequent recovery from drought stress and (2) to determine whether the changes in NA during and following drought stress are related to nodule water potential. Nitrogenase activity of root nodules decreased by more than 80% within 6–8 d of withholding water and recovered 1 or 2 d after watering. Nodule water potential declined significantly from approximately −0.2 MPa to −0.48 MPa with 8 d of stress and recovered to prestress levels within 24 h after watering. Midday abaxial stomatal conductance decreased significantly with stress but recovered within 24 h following watering. Midday leaf water potential did not change significantly during the experimental period. Nodule NA declined 2 d before that of nodule water potential in apparent response to declining soil water content. This response and the lag in the recovery of NA following drought stress after nodule water potential had returned to prestress levels support the hypothesis that nodule water potential per se is not the primary cause for the decline in NA of cowpea root nodules during drought stress.Key words: Vigna unguiculata (L.) Walp., nitrogenase activity, drought stress, recovery, cowpea

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