Root knot nematodes are top priority nematode pests that significantly constrain agricultural productivity globally especially in developing countries. However, expressing double stranded RNA (dsRNA) of essential nema...Root knot nematodes are top priority nematode pests that significantly constrain agricultural productivity globally especially in developing countries. However, expressing double stranded RNA (dsRNA) of essential nematode genes in susceptible plants is known to confer protection against these pests via RNA silencing. This molecular-based strategy is called host induced gene silencing (HIGS) and the selection of appropriate target nematode gene is critical to its success. In this study, therefore, we focused on root knot nematode PolA1, an essential single copy nuclear gene encoding the largest subunit of RNA polymerase I enzyme and evaluated its effectiveness as a target in conferring nematode resistance on Agrobacterium-mediated transformed tobacco plants. Transgenic tobacco expressing Meloidogyne incognita-specific (MiS) dsRNA of PolA1 gene showed significant reduction in nematode fecundity and multiplication compared to wild type plants in both T0 and T1 generations. T0 plants showed varying degrees of agronomic vigorover WT plants possibly due to varying levels of processed siRNA. However, production of MiS siRNAs in the transgenic plants coupled with significant reduction of PolA1 transcript expression in nematodes feeding on roots of transgenic plants provided evidence of HIGS. Taken together, our results show that PolA1 is a potentially effective target for HIGS-mediated reduction of root knot nematode damage on transgenic tobacco. Given the homology of our target sequence among Meloidogyne species, this protection could be broad range against other root knot nematodes aside M. incognita.展开更多
Plant-parasitic nematodes are major threat for crop protection.The lack of nematicides with new mode of action and increasing resistance raises the need for novel nematicides.In order to seek new nematicidal lead,orig...Plant-parasitic nematodes are major threat for crop protection.The lack of nematicides with new mode of action and increasing resistance raises the need for novel nematicides.In order to seek new nematicidal lead,originating from the structure of chalcone,a series of fused ring compounds was obtained by ring closure design strategy.These compounds were modified further.The nematicidal activity against M.incognita of synthesized compounds was evaluated.The bioassay showed that compound 3 and some of its derivatives such as compounds 18,19,21,22,23,24 and 26 exhibited excellent nematicidal activity.Among them,compound 23 exhibited significant bioactivity.The LC50/72 hvalue reached 3.20 mg/L in vitro and the inhibition rate was 100.00%at 40 mg/L in the matrix.The structure-activity relationship of synthesized compounds was discussed in details.The influence of compound 23 on egg hatching,motility,and feeding behavior of C.elegans was also evaluated.展开更多
文摘Root knot nematodes are top priority nematode pests that significantly constrain agricultural productivity globally especially in developing countries. However, expressing double stranded RNA (dsRNA) of essential nematode genes in susceptible plants is known to confer protection against these pests via RNA silencing. This molecular-based strategy is called host induced gene silencing (HIGS) and the selection of appropriate target nematode gene is critical to its success. In this study, therefore, we focused on root knot nematode PolA1, an essential single copy nuclear gene encoding the largest subunit of RNA polymerase I enzyme and evaluated its effectiveness as a target in conferring nematode resistance on Agrobacterium-mediated transformed tobacco plants. Transgenic tobacco expressing Meloidogyne incognita-specific (MiS) dsRNA of PolA1 gene showed significant reduction in nematode fecundity and multiplication compared to wild type plants in both T0 and T1 generations. T0 plants showed varying degrees of agronomic vigorover WT plants possibly due to varying levels of processed siRNA. However, production of MiS siRNAs in the transgenic plants coupled with significant reduction of PolA1 transcript expression in nematodes feeding on roots of transgenic plants provided evidence of HIGS. Taken together, our results show that PolA1 is a potentially effective target for HIGS-mediated reduction of root knot nematode damage on transgenic tobacco. Given the homology of our target sequence among Meloidogyne species, this protection could be broad range against other root knot nematodes aside M. incognita.
基金financial supported by the National Natural Science Foundation of China(No.21672061)National Key Research Program of China(No.2018YFD0200105)+1 种基金supported by Innovation Program of Shanghai Municipal Education Commission(No.201701070002E00037)the Fundamental Research Funds for the Central Universities。
文摘Plant-parasitic nematodes are major threat for crop protection.The lack of nematicides with new mode of action and increasing resistance raises the need for novel nematicides.In order to seek new nematicidal lead,originating from the structure of chalcone,a series of fused ring compounds was obtained by ring closure design strategy.These compounds were modified further.The nematicidal activity against M.incognita of synthesized compounds was evaluated.The bioassay showed that compound 3 and some of its derivatives such as compounds 18,19,21,22,23,24 and 26 exhibited excellent nematicidal activity.Among them,compound 23 exhibited significant bioactivity.The LC50/72 hvalue reached 3.20 mg/L in vitro and the inhibition rate was 100.00%at 40 mg/L in the matrix.The structure-activity relationship of synthesized compounds was discussed in details.The influence of compound 23 on egg hatching,motility,and feeding behavior of C.elegans was also evaluated.
