Micro RNAs(mi RNAs)act as regulators of plant development and multiple stress responses.Here we demonstrate that the rice mi R171 b-SCL6-IIs module regulates the balance between blast resistance,grain yield,and flower...Micro RNAs(mi RNAs)act as regulators of plant development and multiple stress responses.Here we demonstrate that the rice mi R171 b-SCL6-IIs module regulates the balance between blast resistance,grain yield,and flowering.mi R171 b-overexpressing rice plants(OX171 b)displayed increased rice blast resistance accompanied with enhanced defense responses and late heading,whereas blocking mi R171 b expression in rice(MIM171)led to greater susceptibility to blast disease,associated with compromised defense responses and early heading.Either overexpressing or silencing of mi R171 b significantly affected plant height and number of filled seeds per panicle(seed-setting rate),resulting in decreased grain yield.mi R171 b targets SCL6-IIa,SCL6-IIb,and SCL6-IIc,whose expression was suppressed in OX171 b but increased in MIM171.Mutants of SCL6-IIa,SCL6-IIb,and SCL6-IIc all displayed phenotypes like that of OX171 b,including markedly increased blast disease resistance,slightly decreased grain yield,and delayed flowering.Amounts of mi R171 b increased gradually in leaves during the vegetative stage but decreased gradually in panicles during the reproductive stage,whereas SCL6-IIs displayed the reverse expression pattern.Together,these results suggest that the expression of mi R171 b was time-and space-dependent during the rice growth period and regulated the balance between rice blast disease resistance,grain yield,and flowering via SCL6-IIs,and that appropriate accumulation of mi R171 b is essential for rice development.展开更多
Genetic diversity of commercial and local rice cultivars in Yunnan Province was studied using the resistance gene analogue (RGA) based on resistance gene conserved sequences. The RGA analysis of 137 cultivars was cond...Genetic diversity of commercial and local rice cultivars in Yunnan Province was studied using the resistance gene analogue (RGA) based on resistance gene conserved sequences. The RGA analysis of 137 cultivars was conducted by PCR amplification using three primers, i.e. S1/AS3, XLRR for/XLRR rev, and Pto-kinl/Pto-kin2, respectively. The results showed that both Indica and Japonica cultivars were genetically highly diverse. All cultivars were divided into 3 lineages according to the DNA band data at 96% dissimilarity, and into 20 lineages at 60% dissimilarity. The lineages were related to their genetic background and blast disease resistance with only a few exceptions. The RGA data can be useful in rice production by mixed-planting of different cultivars in the field and breeding of resistance cultivars by selecting different parental cultivars with great genetic diversity.展开更多
基金supported by the National Natural Science Foundation of China(U19A2033,31672090,and 31430072)the Sichuan Applied Fundamental Research Foundation(2020YJ0332)to Wenming Wang。
文摘Micro RNAs(mi RNAs)act as regulators of plant development and multiple stress responses.Here we demonstrate that the rice mi R171 b-SCL6-IIs module regulates the balance between blast resistance,grain yield,and flowering.mi R171 b-overexpressing rice plants(OX171 b)displayed increased rice blast resistance accompanied with enhanced defense responses and late heading,whereas blocking mi R171 b expression in rice(MIM171)led to greater susceptibility to blast disease,associated with compromised defense responses and early heading.Either overexpressing or silencing of mi R171 b significantly affected plant height and number of filled seeds per panicle(seed-setting rate),resulting in decreased grain yield.mi R171 b targets SCL6-IIa,SCL6-IIb,and SCL6-IIc,whose expression was suppressed in OX171 b but increased in MIM171.Mutants of SCL6-IIa,SCL6-IIb,and SCL6-IIc all displayed phenotypes like that of OX171 b,including markedly increased blast disease resistance,slightly decreased grain yield,and delayed flowering.Amounts of mi R171 b increased gradually in leaves during the vegetative stage but decreased gradually in panicles during the reproductive stage,whereas SCL6-IIs displayed the reverse expression pattern.Together,these results suggest that the expression of mi R171 b was time-and space-dependent during the rice growth period and regulated the balance between rice blast disease resistance,grain yield,and flowering via SCL6-IIs,and that appropriate accumulation of mi R171 b is essential for rice development.
基金supported by the National 863Project(AA211091)the Natural Science Foundation of China(30160048)Yunnan Agricultural University.
文摘Genetic diversity of commercial and local rice cultivars in Yunnan Province was studied using the resistance gene analogue (RGA) based on resistance gene conserved sequences. The RGA analysis of 137 cultivars was conducted by PCR amplification using three primers, i.e. S1/AS3, XLRR for/XLRR rev, and Pto-kinl/Pto-kin2, respectively. The results showed that both Indica and Japonica cultivars were genetically highly diverse. All cultivars were divided into 3 lineages according to the DNA band data at 96% dissimilarity, and into 20 lineages at 60% dissimilarity. The lineages were related to their genetic background and blast disease resistance with only a few exceptions. The RGA data can be useful in rice production by mixed-planting of different cultivars in the field and breeding of resistance cultivars by selecting different parental cultivars with great genetic diversity.
