Aroma is an important quality parameter for breeding in rice(Oryza sativa).For example,the aromatic rice varieties basmati and jasmine rice,with a popcorn-like scent,are popular worldwide and routinely command a price...Aroma is an important quality parameter for breeding in rice(Oryza sativa).For example,the aromatic rice varieties basmati and jasmine rice,with a popcorn-like scent,are popular worldwide and routinely command a price premium.2-acetyl-1-pyrroline(2AP)is a key flavor compound among over 200 volatiles identified in fragrant rice.A naturally fragrant germplasm exists in multiple plant species besides rice,which all exhibit lower activity of BETAINE ALDEHYDE DEHYDROGENASE 2(BADH2).However,no equivalent aromatic germplasm has been described in maize(Zea mays).Here,we characterized the two maize BADH2 homologs,ZmBADH2a and ZmBADH2b.We generated zmbadh2a and zmbadh2b single mutants and the zmbadh2a-zmbadh2b double mutant by CRISPR/Cas in four inbred lines.A popcorn-like scent was only noticeable in seeds from the double mutant,but not from either single mutant or in wild type.In agreement,we only detected 2AP in fresh kernels and dried mature seeds from the double mutant,which accumulated between 0.028 and 0.723 mg/kg 2AP.These results suggest that ZmBADH2a and ZmBADH2b redundantly participate in 2AP biosynthesis in maize,and represent the creation of the world's first aromatic maize by simultaneous genome editing of the two BADH2 genes.展开更多
The adult lung,a workhorse for gas exchange,is continually subjected to a barrage of assaults from the inhaled particles and pathogens.Hence,homeostatic maintenance is of paramount importance.Epithelial stem cells int...The adult lung,a workhorse for gas exchange,is continually subjected to a barrage of assaults from the inhaled particles and pathogens.Hence,homeostatic maintenance is of paramount importance.Epithelial stem cells interact with their particular niche in the adult lung to orchestrate both natural tissue rejuvenation and robust post-injury regeneration.Advances in single-cell sequencing,lineage tracing,and living tissue imaging have deepened our understanding about stem cell heterogeneities,transition states,and specific cell lineage markers.In this review,we provided an overview of the known stem/progenitor cells and their subpopulations in different regions of the adult lung,and explored the regulatory networks in stem cells and their respective niche which collectively coordinated stem cell quiescence and regeneration states.We finally discussed relationships between dysregulated stem cell function and lung disease.展开更多
文摘Aroma is an important quality parameter for breeding in rice(Oryza sativa).For example,the aromatic rice varieties basmati and jasmine rice,with a popcorn-like scent,are popular worldwide and routinely command a price premium.2-acetyl-1-pyrroline(2AP)is a key flavor compound among over 200 volatiles identified in fragrant rice.A naturally fragrant germplasm exists in multiple plant species besides rice,which all exhibit lower activity of BETAINE ALDEHYDE DEHYDROGENASE 2(BADH2).However,no equivalent aromatic germplasm has been described in maize(Zea mays).Here,we characterized the two maize BADH2 homologs,ZmBADH2a and ZmBADH2b.We generated zmbadh2a and zmbadh2b single mutants and the zmbadh2a-zmbadh2b double mutant by CRISPR/Cas in four inbred lines.A popcorn-like scent was only noticeable in seeds from the double mutant,but not from either single mutant or in wild type.In agreement,we only detected 2AP in fresh kernels and dried mature seeds from the double mutant,which accumulated between 0.028 and 0.723 mg/kg 2AP.These results suggest that ZmBADH2a and ZmBADH2b redundantly participate in 2AP biosynthesis in maize,and represent the creation of the world's first aromatic maize by simultaneous genome editing of the two BADH2 genes.
文摘The adult lung,a workhorse for gas exchange,is continually subjected to a barrage of assaults from the inhaled particles and pathogens.Hence,homeostatic maintenance is of paramount importance.Epithelial stem cells interact with their particular niche in the adult lung to orchestrate both natural tissue rejuvenation and robust post-injury regeneration.Advances in single-cell sequencing,lineage tracing,and living tissue imaging have deepened our understanding about stem cell heterogeneities,transition states,and specific cell lineage markers.In this review,we provided an overview of the known stem/progenitor cells and their subpopulations in different regions of the adult lung,and explored the regulatory networks in stem cells and their respective niche which collectively coordinated stem cell quiescence and regeneration states.We finally discussed relationships between dysregulated stem cell function and lung disease.