Browsing by Author "Kunert, Karl J."

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Defining biotechnological solutions for insect control in sub-Saharan Africa
    (Wiley Open Access, 2019) Botha, Anna-Maria; Kunert, Karl J.; Maling’a, Joyce; Foyer, Christine H.
    Africa is burdened by food insecurity with nearly a billion people suffering from starvation, undernutrition, and malnutrition. Climate change prediction models forecast changes in rainfall patterns and rising temperature regimes, with impacts particularly on Southern and East Africa. These predictions are especially concerning for the production of major food crops, such as maize, sorghum, millet, and groundnut, because median temperature increases are associated with increased pest pressure and changes in migratory patterns. These factors will result in significantly more pest invasions and an increased need for innovative insect management practices. This review focuses on pest control strategies, highlighting important examples, their economic impact, and new alternative pest control strategies. African policymakers remain hesitant to move forward with establishing biosafety laws and commercializing GM crops, and it is often difficult to implement regulatory measures in smallholder agriculture to increase efficacy.
  • Thumbnail Image
    Item
    Expression of a small ubiquitin-like modifier Protease increases drought tolerance in wheat (Triticum aestivum L.)
    (Frontiers, 2019-03-08) Le Roux, Marlon L.; Kunert, Karl J.; Van der Vyver, Christell; Cullis, Christopher A.; Botha, Anna-Maria
    Post-translation modification of proteins plays a critical role in cellular signaling processes. In recent years, the SUMO (Small Ubiquitin-Like Modifier) class of molecules has emerged as an influential mechanism for target protein management. SUMO proteases play a vital role in regulating pathway flux and are therefore ideal targets for manipulating stress-responses. In the present study, the expression of an Arabidopsis thaliana cysteine protease (OVERLY TOLERANT TO SALT-1, OTS1) in wheat (Triticum aestivum L.) has led to improved plant growth under water stress conditions. Transformed wheat (pUBI-OTS1) displayed enhanced growth and delayed senescence under water deficit when compared with untransformed Gamtoos-R genotype or plants carrying an empty vector. Transformed pUBI-OTS1 plants also maintained a high relative moisture content (RMC), had a higher photosynthesis rate, and also had a higher total chlorophyll content when compared to untransformed plants or plants carrying an empty vector. SUMOylation of total protein also increased in untransformed plants but not in the AtOTS1 transformed plants. Our results suggest that SUMO-proteases may influence an array of mechanisms in wheat to the advantage of the crop to be more tolerant to water stress caused by drought. This is the first report to elucidate SUMOylation effects in the hexaploid crop wheat (T. aestivum L.).
  • Thumbnail Image
    Item
    Wheat line “RYNO3936” is associated with delayed water stress-induced leaf senescence and rapid water-deficit stress recovery
    (Frontiers Media, 2020) Le Roux, Marlon-Schylor L.; Burger, N. Francois V.; Vlok, Mare; Kunert, Karl J.; Cullis, Christopher A.; Botha, Anna-Maria
    Random mutagenesis was applied to produce a new wheat mutant (RYNO3926) with superior characteristics regarding tolerance to water deficit stress induced at late booting stage. The mutant also displays rapid recovery from water stress conditions. Under water stress conditions mutant plants reached maturity faster and produced more seeds than its wild type wheat progenitor. Wild-type Tugela DN plants died within 7 days after induction of water stress induced at late booting stage, while mutant plants survived by maintaining a higher relative moisture content (RMC), increased total chlorophyll, and a higher photosynthesis rate and stomatal conductance. Analysis of the proteome of mutant plants revealed that they better regulate post-translational modification (SUMOylation) and have increased expression of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) proteins. Mutant plants also expressed unique proteins associated with dehydration tolerance including abscisic stress-ripening protein, cold induced protein, cold-responsive protein, dehydrin, Group 3 late embryogenesis, and a lipoprotein (LAlv9) belonging to the family of lipocalins. Overall, our results suggest that our new mutant RYNO3936 has a potential for inclusion in future breeding programs to improve drought tolerance under dryland conditions.