Products of plant resistance ( R ) genes Pto and Cf contain distinct domains, and have different cellular localization. It is intriguing to compare the development mechanisms of resistance conferred by the t...Products of plant resistance ( R ) genes Pto and Cf contain distinct domains, and have different cellular localization. It is intriguing to compare the development mechanisms of resistance conferred by the two R genes. In the present report, two hypersensitive response (HR) initiation systems were employed to study the time_course expression induced by Avr / Cf interaction of the genes encoding Pti4, Pti5 and Pti6 which interact directly with Pto: (1) Seeds of tomato (Lycopersicon esculentum Mill.) containing complementary gene pairs Avr 4/ Cf _4 and Avr 9/ Cf _9 were obtained through crossing. Their seedlings developed HR under room temperature. (2) Avr / Cf seedlings grew normally at 33 ℃. When the temperature was shifted down to 25 ℃, HR occurred within hours in the seedlings. Results of both experiments showed that expression of Pti4, Pti5 and Pti6 was induced upon development of hypersensitive necrosis in Avr / Cf seedlings. However, the expression levels and patterns of these Pti s differed. This finding indicated that these Pti s function complementarily, and might be involved in regulation of both Pto and Cf _conferred resistance.展开更多
通过室外大气暴晒试验和电化学腐蚀试验,研究了建筑用新型耐候钢09Mn Cu PTi RE的大气初期腐蚀行为,并进行了腐蚀形貌、腐蚀产物组成和Tafel曲线的测试与分析。结果表明,在SO2含量低于10ppm的室外大气中,该耐候钢的质量变化率在第10天...通过室外大气暴晒试验和电化学腐蚀试验,研究了建筑用新型耐候钢09Mn Cu PTi RE的大气初期腐蚀行为,并进行了腐蚀形貌、腐蚀产物组成和Tafel曲线的测试与分析。结果表明,在SO2含量低于10ppm的室外大气中,该耐候钢的质量变化率在第10天趋于稳定,而在SO2含量为40~60ppm的室外大气中,其质量变化率在第21天趋于稳定;室外大气暴晒后的腐蚀产物由Fe SO4·7H2O和γ-Fe OOH组成;与未通入SO_2的5wt%Na Cl电解液相比,在通入90 ppm SO2的5wt%Na Cl中其腐蚀电位负移了169 m V。展开更多
文摘Products of plant resistance ( R ) genes Pto and Cf contain distinct domains, and have different cellular localization. It is intriguing to compare the development mechanisms of resistance conferred by the two R genes. In the present report, two hypersensitive response (HR) initiation systems were employed to study the time_course expression induced by Avr / Cf interaction of the genes encoding Pti4, Pti5 and Pti6 which interact directly with Pto: (1) Seeds of tomato (Lycopersicon esculentum Mill.) containing complementary gene pairs Avr 4/ Cf _4 and Avr 9/ Cf _9 were obtained through crossing. Their seedlings developed HR under room temperature. (2) Avr / Cf seedlings grew normally at 33 ℃. When the temperature was shifted down to 25 ℃, HR occurred within hours in the seedlings. Results of both experiments showed that expression of Pti4, Pti5 and Pti6 was induced upon development of hypersensitive necrosis in Avr / Cf seedlings. However, the expression levels and patterns of these Pti s differed. This finding indicated that these Pti s function complementarily, and might be involved in regulation of both Pto and Cf _conferred resistance.
