Because of socio-economic importance of date palm in North Africa, the scientific community has always followed the progression of parasitic disease that affects it. The study was performed on population of thirty pal...Because of socio-economic importance of date palm in North Africa, the scientific community has always followed the progression of parasitic disease that affects it. The study was performed on population of thirty palm trees belonging to three cultivars of the oases of south-west Algeria TOUAT Gourara. The analytical protocol consists of a hot hydrochloric acid hydrolysis of I g of leaf material dried and ground. Structural analysis of compounds present in extracts was conducted by chromatographic and spectrophotometric techniques. Through the analysis of all HPLC profiles of phenolic acids, we have established three chemotypes： resistant with the highest heights, sensitive, with the lowest height, finally low sensitivity or tolerant with intermediate heights. The increased synthesis of C-glycoflavones, within diseased palms, can be seen as the first sign of plant response to fungal attack, or even as a defense mechanism so these flavonoids correspond to ＂pre-inhibitines＂. It has not been found qualitative differences between different cultivars studied. The merits of our work show a negative correlation between flavonoid content and the level of lignification in the date palm, suggests that the process of lignification is more rapid in resistant cultivars. We can say that there is a constitutive resistance.展开更多
Bacterial blight caused by Xanthomonas oryzae pv.oryzae(Xoo) is the most harmful bacterial disease of rice worldwide.Previously,we characterized major disease resistance(MR) gene xa25,which confers race-specific resis...Bacterial blight caused by Xanthomonas oryzae pv.oryzae(Xoo) is the most harmful bacterial disease of rice worldwide.Previously,we characterized major disease resistance(MR) gene xa25,which confers race-specific resistance to Xoo strain PXO339.The xa25 is a recessive allele of the SWEET13 locus,but SWEET13's interaction with PXO339 and how efficiently using this locus for rice breeding still need to be defined.Here we show that the SWEET 13 allele from rice Zhenshan 97 is a susceptibility gene to PXO339.Using this allele's promoter to regulate xa25 resulted in disease,suggesting that the promoter is a key determinant in SWEET13 caused disease in Zhanshan 97 after PXO339 infection.PXO339 transcriptionally induces SWEET13 to cause disease.Partial suppressing SWEET13 expression leads to a high level of resistance to PXO339.Thus,the transcriptionally suppressed SWEET13 functions as xa25 in resistance to PXO339.Hybrid rice is widely grown in many countries.However,recessive MR genes have not been efficiently used for disease resistance breeding in hybrid rice production for both parents of the hybrid have to carry the same recessive gene.However,the suppressed SWEET 13 functions dominantly,which will have advantage to improve the resistance of hybrid rice to xa25-incomptible Xoo.展开更多
文摘Because of socio-economic importance of date palm in North Africa, the scientific community has always followed the progression of parasitic disease that affects it. The study was performed on population of thirty palm trees belonging to three cultivars of the oases of south-west Algeria TOUAT Gourara. The analytical protocol consists of a hot hydrochloric acid hydrolysis of I g of leaf material dried and ground. Structural analysis of compounds present in extracts was conducted by chromatographic and spectrophotometric techniques. Through the analysis of all HPLC profiles of phenolic acids, we have established three chemotypes： resistant with the highest heights, sensitive, with the lowest height, finally low sensitivity or tolerant with intermediate heights. The increased synthesis of C-glycoflavones, within diseased palms, can be seen as the first sign of plant response to fungal attack, or even as a defense mechanism so these flavonoids correspond to ＂pre-inhibitines＂. It has not been found qualitative differences between different cultivars studied. The merits of our work show a negative correlation between flavonoid content and the level of lignification in the date palm, suggests that the process of lignification is more rapid in resistant cultivars. We can say that there is a constitutive resistance.
基金supported by the National Natural Science Foundation of China(31330062)the National Key Research and Development Program of Chin(2016YFD0100903)
文摘Bacterial blight caused by Xanthomonas oryzae pv.oryzae(Xoo) is the most harmful bacterial disease of rice worldwide.Previously,we characterized major disease resistance(MR) gene xa25,which confers race-specific resistance to Xoo strain PXO339.The xa25 is a recessive allele of the SWEET13 locus,but SWEET13's interaction with PXO339 and how efficiently using this locus for rice breeding still need to be defined.Here we show that the SWEET 13 allele from rice Zhenshan 97 is a susceptibility gene to PXO339.Using this allele's promoter to regulate xa25 resulted in disease,suggesting that the promoter is a key determinant in SWEET13 caused disease in Zhanshan 97 after PXO339 infection.PXO339 transcriptionally induces SWEET13 to cause disease.Partial suppressing SWEET13 expression leads to a high level of resistance to PXO339.Thus,the transcriptionally suppressed SWEET13 functions as xa25 in resistance to PXO339.Hybrid rice is widely grown in many countries.However,recessive MR genes have not been efficiently used for disease resistance breeding in hybrid rice production for both parents of the hybrid have to carry the same recessive gene.However,the suppressed SWEET 13 functions dominantly,which will have advantage to improve the resistance of hybrid rice to xa25-incomptible Xoo.
