Gene amplification followed by functional diversification is a major force in evolution. A typical example of this is seen in the WUSCHEL-RELATED HOMEOBOX （WOX） gene family, named after the Arabidopsis stem cell reg...Gene amplification followed by functional diversification is a major force in evolution. A typical example of this is seen in the WUSCHEL-RELATED HOMEOBOX （WOX） gene family, named after the Arabidopsis stem cell regulator WUSCHEL. Here we analyze functional divergence in the WOX gene family. Members of the WUS clade, except the cambium stem cell regulator WOX4, can substitute for WUS function in shoot and floral stem cell maintenance to different degrees. Stem cell function of WUS requires a canonical WUS-box, essential for interaction with TPL/TPR co-repressors, whereas the repressive EAR domain is dispensable and the acidic domain seems only to be required for female fertility. In contrast to the WUS clade, members of the ancient WOX13 and the WOX9 clades cannot support stem cell maintenance. Although the homeodomains are interchangeable between WUS and WOX9 clade members, a WUS- compatible homeodomain together with canonical WUS-box is not sufficient for stem cell maintenance. Our results suggest that WOX function in shoot and floral meristems of Arabidopsis is restricted to the modern WUS clade, suggesting that stem cell control is a derived function. Yet undiscovered functional domains in addition to the homeodomain and the WUS-box are necessary for this function.展开更多
Dear Editor, Phytohormones have been described as essential regula- tors of various processes throughout plant life, forming a strong interactive network. Because of this important func- tion, they are central and in...Dear Editor, Phytohormones have been described as essential regula- tors of various processes throughout plant life, forming a strong interactive network. Because of this important func- tion, they are central and integrative modulators form- ing a physiological key interface between plant responses and primary parameters such as genotype, environmental conditions, and developmental status. Consequently, the determination of the phytohormone signature as a key physiological parameter is necessary to understand the correlations between genotype and phenotype, as well as the influence of exogenous modulations on the phenotype （Yin et al., 2004）. Thus, evaluation of the phytohormone signature has to be considered for physiological phenotyp- ing, especially for the improvement of crops or developing strategies for plant protection. This includes the important trait plant immunity, which is determined also by distinct and fine-tuned modulations of phytohormones （Robert- Seilaniantz et al., 2011）.展开更多
文摘Gene amplification followed by functional diversification is a major force in evolution. A typical example of this is seen in the WUSCHEL-RELATED HOMEOBOX （WOX） gene family, named after the Arabidopsis stem cell regulator WUSCHEL. Here we analyze functional divergence in the WOX gene family. Members of the WUS clade, except the cambium stem cell regulator WOX4, can substitute for WUS function in shoot and floral stem cell maintenance to different degrees. Stem cell function of WUS requires a canonical WUS-box, essential for interaction with TPL/TPR co-repressors, whereas the repressive EAR domain is dispensable and the acidic domain seems only to be required for female fertility. In contrast to the WUS clade, members of the ancient WOX13 and the WOX9 clades cannot support stem cell maintenance. Although the homeodomains are interchangeable between WUS and WOX9 clade members, a WUS- compatible homeodomain together with canonical WUS-box is not sufficient for stem cell maintenance. Our results suggest that WOX function in shoot and floral meristems of Arabidopsis is restricted to the modern WUS clade, suggesting that stem cell control is a derived function. Yet undiscovered functional domains in addition to the homeodomain and the WUS-box are necessary for this function.
文摘Dear Editor, Phytohormones have been described as essential regula- tors of various processes throughout plant life, forming a strong interactive network. Because of this important func- tion, they are central and integrative modulators form- ing a physiological key interface between plant responses and primary parameters such as genotype, environmental conditions, and developmental status. Consequently, the determination of the phytohormone signature as a key physiological parameter is necessary to understand the correlations between genotype and phenotype, as well as the influence of exogenous modulations on the phenotype （Yin et al., 2004）. Thus, evaluation of the phytohormone signature has to be considered for physiological phenotyp- ing, especially for the improvement of crops or developing strategies for plant protection. This includes the important trait plant immunity, which is determined also by distinct and fine-tuned modulations of phytohormones （Robert- Seilaniantz et al., 2011）.
