Since the first MADS-box transcription factor genes were implicated in the establishment of floral organ identity in a couple of model plants, the size and scope of this gene family has begun to be appreciated in a mu...Since the first MADS-box transcription factor genes were implicated in the establishment of floral organ identity in a couple of model plants, the size and scope of this gene family has begun to be appreciated in a much wider range of species. Over the course of millions of years the number of MADS-box genes in plants has increased to the point that the Arabidopsis genome contains more than 100. The understanding gained from studying the evolution, regulation and function of multiple MADS-box genes in an increasing set of species, makes this large plant transcription factor gene family an ideal subject to study the processes that lead to an increase in gene number and the selective birth, death and repurposing of its component members. Here we will use examples taken from the MADS-box gene family to review what is known about the factors that influence the loss and retention of genes duplicated in different ways and examine the varied fates of the retained genes and their associated biological outcomes.展开更多
MADS-box genes are involved in floral organ development. Here we report that an AGL6(Agamous-like 6)-like MADS-box gene, HoAGL6, was isolated from Hyacinthus orientalis L. Expression pattern analy-sis demonstrated tha...MADS-box genes are involved in floral organ development. Here we report that an AGL6(Agamous-like 6)-like MADS-box gene, HoAGL6, was isolated from Hyacinthus orientalis L. Expression pattern analy-sis demonstrated that HoAGL6 transcript was detected in inflorescence buds, tepals, carpels and ovules, but not in stamina, leaves or scales. Transgenic Arabidopsis plants ectopically expressing HoAGL6 exhibited novel phenotypes of significantly reduced plant size, extremely early flowering, and losing inflorescence indeterminacy. In addition, wide homeotic conversion of sepals, petals, and leaves into carpel-like or ovary structures, and disappearance or number reduction of stamens in 35S::HoAGL6 Arabidopsis plants were also observed. RT-PCR analysis indicated that the expressions of flowering time gene SOC1 and flower meristem identity gene LFY were significantly up-regulated in 35S::HoAGL6 transgenic Arabidopsis plants, and the expression levels of floral organ identity genes AG and SEP1 in leaves were also elevated. These results indicated that HoAGL6 was involved in the regulation of flower transition and flower organ formation.展开更多
EMBRYONIC FLOWER （EMF） genes are required to maintain vegetative development via repression of flower homeotic genes in Arabidopsis. Removal of EMF gene function caused plants to flower upon germination, producing a...EMBRYONIC FLOWER （EMF） genes are required to maintain vegetative development via repression of flower homeotic genes in Arabidopsis. Removal of EMF gene function caused plants to flower upon germination, producing abnormal and sterile flowers. The pleiotropic effect of ernfl mutation suggests its requirement for gene programs involved in diverse developmental processes. Transgenic plants harboring EMF1 promoter：：glucuronidase （GUS） reporter gene were generated to investigate the temporal and spatial expression pattern of EMF1. These plants displayed differential GUS activity in vegetative and flower tissues, consistent with the role of EMF1 in regulating multiple gene programs. EMFI：：GUS expression pattern in emf mutants suggests organ-specific auto-regulation. Sense- and antisense （as） EMF1 cDNA were expressed under the control of stage- and tissue-specific promoters in transgenic plants. Characterization of these transgenic plants showed that EMF1 activity is required in meristematic as well as differentiating tissues to rescue emf mutant phenotype. Temporal removal or reduction of EMF1 activity in the embryo or shoot apex of wild-type seedlings was sufficient to cause early flowering and terminal flower formation in adult plants. Such reproductive cell memory is reflected in the flower MADS-box gene activity expressed prior to flowering in these early flowering plants. However, temporal removal of EMF1 activity in flower meristem did not affect flower development. Our results are consistent with EMF1＇s primary role in repressing flowering in order to allow for vegetative growth.展开更多
基金funded by the Biotechnology and Biological Sciences Research Council(BBSRC) ERA-NET BB/G024995/1
文摘Since the first MADS-box transcription factor genes were implicated in the establishment of floral organ identity in a couple of model plants, the size and scope of this gene family has begun to be appreciated in a much wider range of species. Over the course of millions of years the number of MADS-box genes in plants has increased to the point that the Arabidopsis genome contains more than 100. The understanding gained from studying the evolution, regulation and function of multiple MADS-box genes in an increasing set of species, makes this large plant transcription factor gene family an ideal subject to study the processes that lead to an increase in gene number and the selective birth, death and repurposing of its component members. Here we will use examples taken from the MADS-box gene family to review what is known about the factors that influence the loss and retention of genes duplicated in different ways and examine the varied fates of the retained genes and their associated biological outcomes.
文摘MADS-box genes are involved in floral organ development. Here we report that an AGL6(Agamous-like 6)-like MADS-box gene, HoAGL6, was isolated from Hyacinthus orientalis L. Expression pattern analy-sis demonstrated that HoAGL6 transcript was detected in inflorescence buds, tepals, carpels and ovules, but not in stamina, leaves or scales. Transgenic Arabidopsis plants ectopically expressing HoAGL6 exhibited novel phenotypes of significantly reduced plant size, extremely early flowering, and losing inflorescence indeterminacy. In addition, wide homeotic conversion of sepals, petals, and leaves into carpel-like or ovary structures, and disappearance or number reduction of stamens in 35S::HoAGL6 Arabidopsis plants were also observed. RT-PCR analysis indicated that the expressions of flowering time gene SOC1 and flower meristem identity gene LFY were significantly up-regulated in 35S::HoAGL6 transgenic Arabidopsis plants, and the expression levels of floral organ identity genes AG and SEP1 in leaves were also elevated. These results indicated that HoAGL6 was involved in the regulation of flower transition and flower organ formation.
文摘EMBRYONIC FLOWER （EMF） genes are required to maintain vegetative development via repression of flower homeotic genes in Arabidopsis. Removal of EMF gene function caused plants to flower upon germination, producing abnormal and sterile flowers. The pleiotropic effect of ernfl mutation suggests its requirement for gene programs involved in diverse developmental processes. Transgenic plants harboring EMF1 promoter：：glucuronidase （GUS） reporter gene were generated to investigate the temporal and spatial expression pattern of EMF1. These plants displayed differential GUS activity in vegetative and flower tissues, consistent with the role of EMF1 in regulating multiple gene programs. EMFI：：GUS expression pattern in emf mutants suggests organ-specific auto-regulation. Sense- and antisense （as） EMF1 cDNA were expressed under the control of stage- and tissue-specific promoters in transgenic plants. Characterization of these transgenic plants showed that EMF1 activity is required in meristematic as well as differentiating tissues to rescue emf mutant phenotype. Temporal removal or reduction of EMF1 activity in the embryo or shoot apex of wild-type seedlings was sufficient to cause early flowering and terminal flower formation in adult plants. Such reproductive cell memory is reflected in the flower MADS-box gene activity expressed prior to flowering in these early flowering plants. However, temporal removal of EMF1 activity in flower meristem did not affect flower development. Our results are consistent with EMF1＇s primary role in repressing flowering in order to allow for vegetative growth.
