Browsing by Author "Egbichi, Ifeanyi"

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    Comparative analysis of responses to field salinity stress in contrasting soybean accessions highlights NaCl exclusion in leaves as a key mechanism for salinity stress tolerance.
    (JOURNAL OF OASIS AGRICULTURE AND SUSTAINABLE DEVELOPMENT, 2021) Akanbi, Musa; Egbichi, Ifeanyi; Ludidi, Ndiko
    Salinity is one of the main limitations to legume productivity in many regions of the world and it is estimated that 50% of all arable land will become affected by salinity by 2050. The impact of field salinity on soybean performance was assessed using two soybean accessions (KCW and HMC) cultivated in salt- treated soil and non-salt treated soil. We used a 30 cm deep field system layered with 0.4 kg/m2 NaCl for the salt-treated experiment while the control field received no salt treatment. The results show that salinity reduces soybean growth and yield as evident from the reduction in the plant shoot length, stem diameter, number of branches, number of pods and seed weight. However, the reduction in these growth parameters was less pronounced in the HMC accession than the KCW accession. Furthermore, Na+ content in leaves of the HMC accession was lower than that of the KCW accession. This proved that salinity has a damaging effect on soybean growth and yield and the relative tolerance of the HMC accession is attributed in part to its ability to restrict Na+ transport to the leaves. While the study emphasizes salt exclusion as a potentially useful mechanism for salinity tolerance in soybean, it provides evidence that the HMC accession is a good genetic resource for breeding soybean varieties with improved salinity stress tolerance.
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    Inhibition of NOS- like activity in maize alters the expression of genes involved in H2O2 scavenging and glycine betaine biosynthesis
    (Nature Publishing Group, 2018) Phillips, Kyle; Majola, Anelisa; Gokul, Arun; Keyster, Marshall; Ludidi, Ndiko; Egbichi, Ifeanyi
    Nitric oxide synthase-like activity contributes to the production of nitric oxide in plants, which controls plant responses to stress. This study investigates if changes in ascorbate peroxidase enzymatic activity and glycine betaine content in response to inhibition of nitric oxide synthase-like activity are associated with transcriptional regulation by analyzing transcript levels of genes (betaine aldehyde dehydrogenase) involved in glycine betaine biosynthesis and those encoding antioxidant enzymes (ascorbate peroxidase and catalase) in leaves of maize seedlings treated with an inhibitor of nitric oxide synthase-like activity. In seedlings treated with a nitric oxide synthase inhibitor, transcript levels of betaine aldehyde dehydrogenase were decreased. In plants treated with the nitric oxide synthase inhibitor, the transcript levels of ascorbate peroxidase-encoding genes were down-regulated. We thus conclude that inhibition of nitric oxide synthase-like activity suppresses the expression of ascorbate peroxidase and betaine aldehyde dehydrogenase genes in maize leaves. Furthermore, catalase activity was suppressed in leaves of plants treated with nitric oxide synthase inhibitor; and this corresponded with the suppression of the expression of catalase genes. We further conclude that inhibition of nitric oxide synthase-like activity, which suppresses ascorbate peroxidase and catalase enzymatic activities, results in increased H2O2 content.