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Short-term variations in temperature associated with climate change have been noted to affect the physiological processes and metabolite profile of plants, including the nutritional status, ultimately affecting their growth and development. An evaluation of the effects of elevated temperatures on the growth and nutritional quality of cowpea was performed during this experiment. The main objective was to evaluate the effects of short-term elevated temperatures on the nutritional quality of cowpea at different growth stages. Surface-sterilized seeds of cowpea (cv. Soronko) were germinated in pots in the glasshouse. At different growth stages (preflowering, flowering, and postflowering), plants were incubated in growth chambers set at three different temperature regimes (25, 30, and 35 °C) for a period of 7 days. Compared with control (25 °C), exposure to both elevated temperatures (30 and 35 °C) reduced the whole plant fresh weight and dry weight by 30% and 52% and 42% and 29%, respectively, at the preflowering stage, and by 31 and 60% and 47 and 63%, respectively, at the flowering/anthesis stage. However, no significant difference in whole plant biomass was noted between elevated temperatures (35%) and the control temperature at the postflowering stage. Short-term exposure to an elevated temperature (35 °C) increased the shoot crude protein content (5.59 N%) of cowpea compared with control (3.77 N%) and preflowering stage. In contrast, at the flowering stage, an elevated temperature (35 °C) reduced the crude protein content (1.77%) of the shoot compared with control (5.59%). At an elevated temperature (35 °C), the preflowering and flowering stages of cowpea were most affected compared with control. These results suggest that the preflowering and flowering stages of cowpea compared with the postflowering stage are more susceptible to elevated temperatures (30 to 35 °C).

This study was conducted to evaluate the response of bush tea (Athrixia phylicoides DC.) to rainfall, relative humidity and temperature. Four sites, namely, Haenertsburg, Witvlag, and two sites at Khalavha in the Limpopo Province of South Africa were selected for investigation. Data on average rainfall, relative humidity and temperature were obtained 90 days prior to each field visit. During the five field visits over a 3-year period (2014–2016), bush tea plant height and stem diameter were measured and leaves were counted per plant. Correlation analyses suggested that bush tea height, stem diameter and number of leaves per plant significantly (p

This study evaluated the interaction of Bacillus subtilis (BD233) co-inoculation and mine water (75% MW) irrigation on the growth, nodulation, physiology and nutritional quality of cowpea. Three cowpea genotypes were exposed to four treatments namely i) Co-inoculation with B. subtilis (B+) and irrigation with 75% MW, ii) Co-inoculation with B. subtilis (B+) and tap water irrigation (0% MW), iii) No B. subtilis co-inoculation (B-) and irrigation with 75% MW and iv) No co-inoculation with B. subtilis (B-) and irrigation with tap water (0% MW) (control). A factorial experiment was repeated once in a glasshouse using a randomized complete block design with five replications. The results showed that at 125 DAP, Nyira and Asetanapa, not co-inoculated with B. subtilis (B-) and irrigated with 0% MW showed significantly higher number of branches per plant whilst Soronko irrigated with 0% MW but co-inoculated with B. subtilis (B+) had the tallest plants with a corresponding higher biomass compared to the other treatments. With 0% MW irrigation, Soronko and Nyira co-inoculated with B. subtilis (B+) had the highest nodule counts, plant pod counts, pod fresh weight, pod dry weight, number of seeds and seeds fresh weight per plant compared to Asetenapa and control. Co-inoculation with B. subtilis affected heavy metals (Ca, Fe, Zn, Mn & Al) accumulation in shoot and grain of the tested cowpea genotypes. These findings clearly suggest that B. subtilis has ability to sequester heavy metals in soils polluted with mine water and also enhance the growth, nodulation and yield of an important economic crop.

Nutrient-poor soils coupled with micronutrient deficiency among many rural resource-poor communities remain a challenge in sub-Saharan Africa. Nutrient-poor soils can be managed through various soil amendment or fertilisation strategies. Micronutrients can be supplied through plants. The study was aimed at determining the symbiotic nitrogen fixation of cowpea as well as the contribution of inter-cropping under varying levels of nitrogen, phosphorus, and potassium (NPK) fertilisation. In addition, the amount of micronutrients supplied by cowpea and amaranth were determined. The experiment was laid out in a 2 &times, 4 factorial treatment structure in a completely randomised design, with inter-cropping (cowpea and amaranth) and fertiliser (control, 25%, 50%, and 100% of the recommended NPK levels) as treatment factors with four replications. Symbiotic N2 fixation of cowpea decreased from 341&ndash, 448 kgN.ha&minus, 1 to 77&ndash, 91 kgN.ha&minus, 1 for the first year and 557&ndash, 227 kgN.ha&minus, 1 to 92&minus, 164 kgN.ha&minus, 1 for the second year with fertilisation. The iron and zinc nutritional yield increased (61&ndash, 210 g.ha&minus, 1 for first year and 304&ndash, 867 g.ha&minus, 1, for second year), proportional to fertiliser application to both crops. The research shows the benefits of leguminous crops in soil nutrient fertility and inorganic fertilisation with inter-cropping in managing micronutrient deficiency to meet the nutritional needs of rural communities.

Bacillus species are ubiquitous microorganisms that enhance growth in several crops as well as provide protection against pathogens. In this study, the effects of soil inoculation with B. subtilis BD233 on growth and development of sweet pepper (Capsicum annuum L.), Swiss chard (Beta vulgaris L.) and lettuce (Lactuca sativa L.), were investigated. Three treatments were employed: i) incubation with a lysogeny broth culture of B. subtilis BD233; ii) broth without B. subtilis BD233 (without BD233/control) and iii) tap water. Potting soil-grown seedlings of the three crops were assayed to measure growth parameters over a period of five weeks (35 days) after exposure to the treatments. Soil inoculation with B. subtilis BD233 significantly improved the growth and development of sweet pepper and lettuce seedlings relative to the other treatments but not for Swiss chard. Bacillus subtilis BD233 in lysogeny broth increased the plant height, stem elongation rate and stem diameter of sweet pepper and lettuce seedlings relative to those treated with water. Furthermore, the biomass of sweet pepper and lettuce seedlings exposed to B. subtilis BD233 was increased by 32.2 and 92.6%, relative to their respective controls. However, no statistical differences for height and biomass were found for Swiss chard in response to the treatments. The results of the study demonstrated the potential of B. subtilis BD233 to enhance the early growth of these non-indigenous vegetables in nutrient-poor African soils.

Lumichrome is a novel multitrophic signal molecule produced by rhizobia and plants that affects many physiological functions including seedling growth, root respiration, photosynthetic rates, leaf stomatal conductance and transpiration in several plant species. The effect of lumichrome on seed germination of four legumes (Rooibos, cowpea, Bambara groundnut and Kersting's bean), and three non-leguminous crops (traditional pumpkin, makataan and spinach), was investigated. All seeds were surface-sterilized and treated for 2 h with either of three levels of lumichrome (0, 5 or 50 nM). Seed germination (two replicates of ten seeds per crop) was done under sterile conditions using 9 cm-plastic petri dishes and Whatman No. 1 filter paper discs moistened with sterile distilled water. Treating legume seeds with nanomolar concentrations of lumichrome enhanced the seed germination percentage and rate of germination of Kersting's bean seeds, but not those of cowpea when compared to the control. Similarly, no significant differences in seed germination were recorded for Rooibos and Bambara groundnut, however, 9 days after treatment with lumichrome, slight stimulation of seed germination was observed for Rooibos and Bambara groundnut soaked in 5 nM lumichrome, compared to their respective controls. In response to nanomolar concentrations of lumichrome, non-leguminous crops also responded differently. A low nanomolar concentration of lumichrome (5 nM) significantly (p

Leading crops such as cotton, maize, rice and wheat were the first to be studied using omics technologies (genomics, transcriptomics, proteomics and metabolomics). Those crops that are considered l...

Bambara groundnut (Vigna subterranea (L.) Verdc.) [BGN] is an easy-to-cultivate vegetable crop neglected over the past years. It is a drought-tolerant crop with nutritional and medicinal values and as a result, the crop is referred to as nutraceuticals. Based on this, there exist a need to review the beneficial potential (nutraceutical value) of this neglected and underutilized crop to protect and promote its cultivation for food (source of nutrients) and medicines especially among rural poor communities in sub-Saharan Africa. This review systematically examines the background information and uses of BGN. The antimicrobial properties of BGN were also considered and examined to ascertain its nutraceutical importance. BGN has been reported as a crop possessing antioxidant and antimicrobial properties. Clinically, the extracts of BGN have been reported to exhibit antimicrobial activities against bacteria such as Klebsiella pneumoniae subsp. pneumoniae ATCC 700603, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus subsp. aureus ATCC 33591, Escherichia coli, Bacillus cereus, yeast (Candida albicans) and mold (Aspergillus niger). This review outlines the uses of BGN as a functional food crop as well as its nutraceutical and antimicrobial potentials. However, there exist paucity of knowledge and literature on the crop's antimicrobial activities especially against plant pathogens of economic importance. Hence, this review proposes that more research be geared towards assessing the nutraceutical value and antimicrobial potentials of this crop against plant pathogens of economic importance and the promotion of the crop's cultivation., Food Science; Nutrition; Agriculture; Nutraceuticals; Antimicrobial Potential; Bambara Groundnut; Antioxidants; Plant Pathogens; Phytochemicals.

There is little information on in situ distribution of nutrient elements in N2-fixing nodules. The aim of this study was to quantify elemental distribution in tissue components of N2-fixing nodules harvested from Psoralea pinnata plants grown naturally in wetland and upland conditions in the Cape Fynbos. The data obtained from particle-induced X-ray emission revealed the occurrence of 20 elements (Si, P, S, Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, As, Br, Rb, Sr, Y, Zr, Mo and Ba) in nodule components. Although, in upland plants, the concentrations of S, Fe, Si, Mn and Cu showed a steady increase from the middle cortex to the medulla region of P. pinnata nodules, in wetland plants, only S, Fe and Mn showed an increase in concentration from the middle cortex to the bacteria-infected medulla of P. pinnata nodules. By contrast, the concentrations of Cl, K, Ca, Zn and Sr decreased from middle cortex to nodule medulla. The alkaline earth, alkali and transition elements Rb, Sr, Y and Zr, never before reported in N2-fixing nodules, were found to occur in root nodules of P. pinnata plants grown in both wetland and upland conditions.

Soils of the Cape Fynbos in South Africa are very low in nutrients, especially N and P, which affect bacterial growth and metabolism. In this study, the effect of supplying nitrate (14.8 and 59.3 mM NO 3 − ), ammonium (28.1 and 112.0 mM NH 4 + ) and phosphorus (1.4 and 5.7 mM P) to five N2-fixing and 11 non-nodulating bacterial strains isolated from root nodules of Psoralea species in the Cape Fynbos was assessed. The data revealed marked variation in the secretion of lumichrome, riboflavin and IAA into culture filtrate. There was generally greater production of lumichrome, riboflavin and IAA by the N2-fixing bacteria than those unable to nodulate P. pinnata and siratro, with much greater concentrations of lumichrome and riboflavin in culture filtrate at high P than low P. At low and high P, symbiotic strain TUT57pp produced 2.2-fold and 3.2-fold more IAA than TUT65prp and TUT33pap respectively, (two non-nodulating strains also with greater IAA production). Although ammonium nutrition has no effect on riboflavin production, it altered lumichrome concentrations in culture filtrate. While ammonium application had no effect, supplying bacterial cells with high nitrate concentration significantly decreased cellular production of lumichrome and riboflavin, two important symbiotic signal molecules. The observed nitrate inhibition of lumichrome and riboflavin biosynthesis and release is in addition to its depressive effect on nodulation and N2 fixation in symbiotic legumes.

Using thin-layer chromatography, 16 bacterial isolates from root nodules of 8 differentPsoralea species were quantitatively assessed for their exudation of the metabolites lumichrome, riboflavin and IAA in response to pH, salinity and temperature. Our data showed that the bacterial strains tested differed in their levels of secretion of the three metabolites. For example, strain AS2 produced significantly greater amounts of lumichrome at both pH 5.1 and 8.1, while strains RT1 and PI produced more lumichrome per cell at only pH 8.1. Strains API and RP2 also produced more riboflavin at pH 5.1 than at pH 8.1; conversely strain RTl secreted more riboflavin at pH 8.1 than at pH 5.1. TwoP. repens strains (RP1 and RP2) isolated from very saline environments close to the Indian Ocean produced significant levels of lumichrome and riboflavin at both low and high salinity treatments. However, strains ACI and LI (fromP. aculeata andP. laxa) even produced greater amounts of lumichrome and riboflavin at higher salinity (i.e. 34.2 mM NaCl) and probably originated from naturally saline soils. In this study, high acidity and high temperature induced the synthesis and release of high levels of IAA by bacterial cells. In contrast, there was greater strain secretion of lumichrome at lower temperature (10°C) than at high temperature (30°C). The variations in the secretion of lumichrome, riboflavin and IAA by bacterial strains exposed to different pH, salinity and temperature regimes suggest that genes encoding these metabolites are regulated differently by the imposed environmental factors. The data from this study also suggest that natural changes of pH, salinity and/or temperature in plant rhizospheres could potentially elevate the concentrations of lumichrome, riboflavin and IAA in soils. An accumulation of these molecules in the rhizosphere would have consequences for ecosystem functioning as both lumichrome and riboflavin have been reported to act as developmental signals that affect species in all three plant, animal, and microbial kingdoms.