The δ13C value is widely used to assess the effects of drought on water status in plants. However, there is little information regarding the δ13C signature in different organs of rice. We conducted a field study to ...The δ13C value is widely used to assess the effects of drought on water status in plants. However, there is little information regarding the δ13C signature in different organs of rice. We conducted a field study to examine whether the δ13C among different plant parts would be affected by the intensities of drought, and to evaluate genotypic variation in δ13C fluctuation among plant parts affected by drought intensities. Two cultivars, “Nipponbare” (Oryzasativa ssp. japonica) and “Kasalath” (O. sativa ssp. indica), were grown in the field with a line-source sprinkler system. The δ13C values of panicles, flag leaves, straws, culms, and roots were measured from plant samples. The δ13C value increased as drought stress increased, especially in the panicles and roots. “Nipponbare” showed higher values of δ13C than “Kasalath” under the well-watered and mild drought stress conditions, but there was no significant difference between the genotypes in the δ13C value under the severe drought stress condition. The variation in δ13C value among different plant parts was also increased with increasing drought stress. In contrast, these variations were small under well-watered conditions. Furthermore, there was much greater variation in the δ13C value among different plant parts in “Kasalath” than in “Nipponbare” when the plants were grown under drought stress conditions. A significant negative relationship was observed between the δ13C value of panicles and shoot dry matter production, suggesting that the δ13C value of panicles may be the best indicator of plant water status in rice.展开更多
Eusocial insects display a caste system in which different castes are morpho-logically and physiologically specialized for different tasks.Recent studies have revealed that epigenetic modifications,including DNA methy...Eusocial insects display a caste system in which different castes are morpho-logically and physiologically specialized for different tasks.Recent studies have revealed that epigenetic modifications,including DNA methylation and histone modification,me-diate caste determination and differentiation,longevity,and polyethism in eusocial insects.Although there has been a growing interest in the relationship between epigenetic mech-anisms and phenotypic plasticity in termites,there is ltte information about differential expression levels among castes and expression sites for these genes in termites.Here we show royaltissuc-specific expression of epigenetic modification genes in the termite Reticulitermes speratus.Using RNA-seq,we identified 74 genes,including three DNA methyltransferases,seven sirtuins,48 Trithorax group proteins,and 16 Polycomb group proteins.Among these genes,15 showed king-specific expression,and 52 showed age-dependent differential expression in kings and queens.Quantitative real-time PCR revealed that DNA methyltransferase 3 is expressed specifically in the king's testis and fat body,whereas some histone modification genes are remarkably expressed in the king's testis and queen's ovary.These findings imply that epigenetic modification plays important roles in the gamete production process in termite kings and queens.展开更多
文摘The δ13C value is widely used to assess the effects of drought on water status in plants. However, there is little information regarding the δ13C signature in different organs of rice. We conducted a field study to examine whether the δ13C among different plant parts would be affected by the intensities of drought, and to evaluate genotypic variation in δ13C fluctuation among plant parts affected by drought intensities. Two cultivars, “Nipponbare” (Oryzasativa ssp. japonica) and “Kasalath” (O. sativa ssp. indica), were grown in the field with a line-source sprinkler system. The δ13C values of panicles, flag leaves, straws, culms, and roots were measured from plant samples. The δ13C value increased as drought stress increased, especially in the panicles and roots. “Nipponbare” showed higher values of δ13C than “Kasalath” under the well-watered and mild drought stress conditions, but there was no significant difference between the genotypes in the δ13C value under the severe drought stress condition. The variation in δ13C value among different plant parts was also increased with increasing drought stress. In contrast, these variations were small under well-watered conditions. Furthermore, there was much greater variation in the δ13C value among different plant parts in “Kasalath” than in “Nipponbare” when the plants were grown under drought stress conditions. A significant negative relationship was observed between the δ13C value of panicles and shoot dry matter production, suggesting that the δ13C value of panicles may be the best indicator of plant water status in rice.
文摘Eusocial insects display a caste system in which different castes are morpho-logically and physiologically specialized for different tasks.Recent studies have revealed that epigenetic modifications,including DNA methylation and histone modification,me-diate caste determination and differentiation,longevity,and polyethism in eusocial insects.Although there has been a growing interest in the relationship between epigenetic mech-anisms and phenotypic plasticity in termites,there is ltte information about differential expression levels among castes and expression sites for these genes in termites.Here we show royaltissuc-specific expression of epigenetic modification genes in the termite Reticulitermes speratus.Using RNA-seq,we identified 74 genes,including three DNA methyltransferases,seven sirtuins,48 Trithorax group proteins,and 16 Polycomb group proteins.Among these genes,15 showed king-specific expression,and 52 showed age-dependent differential expression in kings and queens.Quantitative real-time PCR revealed that DNA methyltransferase 3 is expressed specifically in the king's testis and fat body,whereas some histone modification genes are remarkably expressed in the king's testis and queen's ovary.These findings imply that epigenetic modification plays important roles in the gamete production process in termite kings and queens.
