It has long been thought that growth‐regulating factors（GRFs） gene family members act as transcriptional activators to play important roles in multiple plant developmental processes. However, the recent characteriz...It has long been thought that growth‐regulating factors（GRFs） gene family members act as transcriptional activators to play important roles in multiple plant developmental processes. However, the recent characterization of Arabidopsis GRF7 showed that it functions as a transcriptional repressor of osmotic stress‐responsive genes. This highlights the complex and diverse mechanisms by which different GRF members use to take action. In this study, the maize（Zea mays L.） GRF10 was functionally characterized to improve this concept. The deduced ZmGRF10 protein retains the N‐terminal QLQ and WRC domains, the characteristic regions as protein‐interacting and DNA‐binding domains, respectively. However,it lacks nearly the entire C‐terminal domain, the regions executing transactivation activity. Consistently, ZmGRF10 protein maintains the ability to interact with GRF‐interacting factors（GIFs） proteins, but lacks transactivation activity.Overexpression of ZmGRF10 in maize led to a reduction in leaf size and plant height through decreasing cell proliferation,whereas the yield‐related traits were not affected. Transcriptome analysis revealed that multiple biological pathways were affected by ZmGRF10 overexpression, including a few transcriptional regulatory genes, which have been demonstrated to have important roles in controlling plant growth and development. We propose that ZmGRF10 aids in fine‐tuning the homeostasis of the GRF‐GIF complex in the regulation of cell proliferation.展开更多
Rice grain filling determines grain weight, final yield and grain quality. Here, a rice defective grain filling mutant, gif2, was identified. Grains ofgif2 showed a slower filling rate and a significant lower final gr...Rice grain filling determines grain weight, final yield and grain quality. Here, a rice defective grain filling mutant, gif2, was identified. Grains ofgif2 showed a slower filling rate and a significant lower final grain weight and yield compared to wild-type. The starch content in gilt2 was noticeably decreased and its physicochemical properties were also altered. Moreover, gif2 endosperm cells showed obvious defects in compound granule formation. Posi- tional cloning identified GIF2 to encode an ADP-glucose pyrophosphorylase （AGP） large subunit, AGPL2; consequently, AGP enzyme activity in gif2 endosperms was remarkably decreased. GIF2 is mainly expressed in developing grains and the coded protein localizes in the cytosol. Yeast two hybrid assay showed that GIF2 interacted with AGP small subunits OsAGPS% OsAGPS2a and OsAGPS2b. Transcript levels for granule-bound starch synthase, starch synthase, starch branching enzyme and starch debranching enzyme were distinctly elevated in gif2 grains. In addition, the level of nucleotide diversity of the GIF2 locus was extremely low in both cultivated and wild rice. All of these results suggest that GIF2 plays important roles in the regulation of grain filling and starch biosynthesis during caryopsis development, and that it has been preserved during selection throughout domestication of modern rice.展开更多
Efficient genetic transformation has the potential to advance research and breeding in watermelon(Citrullus lanatus),but regeneration from tissue culture remains challenging.Previous work showed that expressing a fusi...Efficient genetic transformation has the potential to advance research and breeding in watermelon(Citrullus lanatus),but regeneration from tissue culture remains challenging.Previous work showed that expressing a fusion of two interacting transcription factors,GROWTH-REGULATING FACTOR4(GRF4)and GRF-INTERACTING FACTOR1(GIF1),improved regeneration in wheat(Triticum aestivum).By overexpressing a chimeric fusion of Cl GRF4 and Cl GIF1,we achieved highly efficient transformation in watermelon.Mutating the mi396 micro RNA target site in Cl GRF further boosted the transformation efficiency up to 67.27%in a genotype-independent manner.Cl GRF4-GIF1 can also be combined with clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)genome editing tools to achieve highly efficient gene editing in watermelon,which we used to successfully create diploid seedless watermelon.This research thus puts forward a powerful transformation tool for future watermelon research and breeding.展开更多
基金supported by the National Transgene Research and Industrialization Project of China (2011ZX08003-003-00A)the National High Technology Research and Development Program of China (2012AA10A305)National Program on Key Basic Research Project of China (2014CB147300)
文摘It has long been thought that growth‐regulating factors（GRFs） gene family members act as transcriptional activators to play important roles in multiple plant developmental processes. However, the recent characterization of Arabidopsis GRF7 showed that it functions as a transcriptional repressor of osmotic stress‐responsive genes. This highlights the complex and diverse mechanisms by which different GRF members use to take action. In this study, the maize（Zea mays L.） GRF10 was functionally characterized to improve this concept. The deduced ZmGRF10 protein retains the N‐terminal QLQ and WRC domains, the characteristic regions as protein‐interacting and DNA‐binding domains, respectively. However,it lacks nearly the entire C‐terminal domain, the regions executing transactivation activity. Consistently, ZmGRF10 protein maintains the ability to interact with GRF‐interacting factors（GIFs） proteins, but lacks transactivation activity.Overexpression of ZmGRF10 in maize led to a reduction in leaf size and plant height through decreasing cell proliferation,whereas the yield‐related traits were not affected. Transcriptome analysis revealed that multiple biological pathways were affected by ZmGRF10 overexpression, including a few transcriptional regulatory genes, which have been demonstrated to have important roles in controlling plant growth and development. We propose that ZmGRF10 aids in fine‐tuning the homeostasis of the GRF‐GIF complex in the regulation of cell proliferation.
基金supported by the Natural Science Foundation of China(grants No.31161140348,31471472,31301303,31161140348)by the National S&T Major Project (2014ZX08001006,2016ZX08001006)
文摘Rice grain filling determines grain weight, final yield and grain quality. Here, a rice defective grain filling mutant, gif2, was identified. Grains ofgif2 showed a slower filling rate and a significant lower final grain weight and yield compared to wild-type. The starch content in gilt2 was noticeably decreased and its physicochemical properties were also altered. Moreover, gif2 endosperm cells showed obvious defects in compound granule formation. Posi- tional cloning identified GIF2 to encode an ADP-glucose pyrophosphorylase （AGP） large subunit, AGPL2; consequently, AGP enzyme activity in gif2 endosperms was remarkably decreased. GIF2 is mainly expressed in developing grains and the coded protein localizes in the cytosol. Yeast two hybrid assay showed that GIF2 interacted with AGP small subunits OsAGPS% OsAGPS2a and OsAGPS2b. Transcript levels for granule-bound starch synthase, starch synthase, starch branching enzyme and starch debranching enzyme were distinctly elevated in gif2 grains. In addition, the level of nucleotide diversity of the GIF2 locus was extremely low in both cultivated and wild rice. All of these results suggest that GIF2 plays important roles in the regulation of grain filling and starch biosynthesis during caryopsis development, and that it has been preserved during selection throughout domestication of modern rice.
基金supported by the National Youth Talent Program(A279021801)the Fundamental Research Fund from Northwest A&F University(Z1090221008)the Key R&D Project from Yangling Seed Industry Innovation Center(2021)。
文摘Efficient genetic transformation has the potential to advance research and breeding in watermelon(Citrullus lanatus),but regeneration from tissue culture remains challenging.Previous work showed that expressing a fusion of two interacting transcription factors,GROWTH-REGULATING FACTOR4(GRF4)and GRF-INTERACTING FACTOR1(GIF1),improved regeneration in wheat(Triticum aestivum).By overexpressing a chimeric fusion of Cl GRF4 and Cl GIF1,we achieved highly efficient transformation in watermelon.Mutating the mi396 micro RNA target site in Cl GRF further boosted the transformation efficiency up to 67.27%in a genotype-independent manner.Cl GRF4-GIF1 can also be combined with clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)genome editing tools to achieve highly efficient gene editing in watermelon,which we used to successfully create diploid seedless watermelon.This research thus puts forward a powerful transformation tool for future watermelon research and breeding.
