Plantain is an important crop that serves as a staple food and contributes significantly to income generation for millions of people in tropical and sub-Saharan Africa. Its cultivation faces the main constraint of see...Plantain is an important crop that serves as a staple food and contributes significantly to income generation for millions of people in tropical and sub-Saharan Africa. Its cultivation faces the main constraint of seedlings unavailability in quantity and quality, essential for the creation of new plantations. The advent and popularization of the plantlets from stem bits (PIF) in the 2000s raised hopes for solving this problem. However, after about ten years, the PIF has shown some problems limiting its adoption and should be improved for more efficiency. The amendment of PIF substrate production with Tithonia diversifolia could be an alternative to seedlings’ unavailability. This study aims to evaluate the potential stimulative effect of T. diversifolia mulch on plantain PIF seedlings growth and protection against black Sigatoka disease (BSD)caused by Mycosphaerella fijiensis. The parameters of vegetative growth stages and biomarkers accumulation were assessed in sterilized substrate and non-sterilized substrate conditions. T. diversifolia mulch treatment increases the germination rate, the number of shoots, the height and the diameter of shoots, the leaf area as well as the seedlings roots, but it also protects the seedlings against BSD up to about 81% compared to the control seedlings. It also enhances the accumulation of biomarkers such as proteins, polyphenols content and defense-related enzymes (peroxidase, polyphenol oxidase and glucanase). T. diversifolia mulch seems to act in PIF seedlings production as a vital stimulator. It can therefore be taken as a tool for a more sustainable and resilient agriculture, and for poverty alleviation of poor small holder farmers.展开更多
Mycosphazine A(1), a new iron(Ⅲ) chelator of coprogen-type siderophore, and mycosphamide A(2), a new cyclic amide benzoate, together with six known aryl amides(3-8), were isolated from the fermentation broth of the d...Mycosphazine A(1), a new iron(Ⅲ) chelator of coprogen-type siderophore, and mycosphamide A(2), a new cyclic amide benzoate, together with six known aryl amides(3-8), were isolated from the fermentation broth of the deep-sea-derived fungus Mycosphaerella sp. SCSIO z059. Alkaline hydrolysis of 1 afforded a new epimer of dimerum acid, mycosphazine B(1 a), and a new bi-fusarinine-type siderophore, mycosphazine C(1 b). The planar structures of the new compounds were elucidated by extensive spectroscopic data analysis. The absolute configurations of amino acid residues in 1 a and 1 b were determined by acid hydrolysis. And the absolute configuration of 2 was established by quantum chemical calculations of the electronic circular dichroism(ECD) spectra. Compound 1 is the first siderophore-Fe(Ⅲ) chelator incorporating both L-ornithine and D-ornithine unites. Compounds 3-8 were reported as natural products for the first time, and the 1 H and 13 C NMR data of 6 and 8 were assigned for the first time. Compounds 1 and 1 a could greatly promote the biofilm formation of bacterium Bacillus amyloliquefaciens with the rate of about 249% and 524% at concentration of 100 μg·mL-1, respectively.展开更多
文摘Plantain is an important crop that serves as a staple food and contributes significantly to income generation for millions of people in tropical and sub-Saharan Africa. Its cultivation faces the main constraint of seedlings unavailability in quantity and quality, essential for the creation of new plantations. The advent and popularization of the plantlets from stem bits (PIF) in the 2000s raised hopes for solving this problem. However, after about ten years, the PIF has shown some problems limiting its adoption and should be improved for more efficiency. The amendment of PIF substrate production with Tithonia diversifolia could be an alternative to seedlings’ unavailability. This study aims to evaluate the potential stimulative effect of T. diversifolia mulch on plantain PIF seedlings growth and protection against black Sigatoka disease (BSD)caused by Mycosphaerella fijiensis. The parameters of vegetative growth stages and biomarkers accumulation were assessed in sterilized substrate and non-sterilized substrate conditions. T. diversifolia mulch treatment increases the germination rate, the number of shoots, the height and the diameter of shoots, the leaf area as well as the seedlings roots, but it also protects the seedlings against BSD up to about 81% compared to the control seedlings. It also enhances the accumulation of biomarkers such as proteins, polyphenols content and defense-related enzymes (peroxidase, polyphenol oxidase and glucanase). T. diversifolia mulch seems to act in PIF seedlings production as a vital stimulator. It can therefore be taken as a tool for a more sustainable and resilient agriculture, and for poverty alleviation of poor small holder farmers.
基金the Guangdong Provincial-level Special Funds for Promoting High-quality Economic Development (No. 2020032)Natural science foundation of Guangdong province (No. 2017A030313235)+1 种基金Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)(No. GML2019-ZD0406)National Natural Science Foundation of China (No.81673326).
文摘Mycosphazine A(1), a new iron(Ⅲ) chelator of coprogen-type siderophore, and mycosphamide A(2), a new cyclic amide benzoate, together with six known aryl amides(3-8), were isolated from the fermentation broth of the deep-sea-derived fungus Mycosphaerella sp. SCSIO z059. Alkaline hydrolysis of 1 afforded a new epimer of dimerum acid, mycosphazine B(1 a), and a new bi-fusarinine-type siderophore, mycosphazine C(1 b). The planar structures of the new compounds were elucidated by extensive spectroscopic data analysis. The absolute configurations of amino acid residues in 1 a and 1 b were determined by acid hydrolysis. And the absolute configuration of 2 was established by quantum chemical calculations of the electronic circular dichroism(ECD) spectra. Compound 1 is the first siderophore-Fe(Ⅲ) chelator incorporating both L-ornithine and D-ornithine unites. Compounds 3-8 were reported as natural products for the first time, and the 1 H and 13 C NMR data of 6 and 8 were assigned for the first time. Compounds 1 and 1 a could greatly promote the biofilm formation of bacterium Bacillus amyloliquefaciens with the rate of about 249% and 524% at concentration of 100 μg·mL-1, respectively.
