Role of methylation in vernalization and photoperiod pathway:a potential flowering regulator?

Recognized as a pivotal developmental transition,flowering marks the continuation of a plant’s life cycle.Vernalization and pho-toperiod are two major flowering pathways orchestrating numerous florigenic signals.Methylation,including histone,DNA and RNA methylation,is one of the recent foci in plant development.Considerable studies reveal that methylation seems to show an increasing potential regulatory role in plant flowering via altering relevant gene expression without altering the genetic basis.However,little has been reviewed about whether and how methylation acts on vernalization-and photoperiod-induced flowering before and after FLOWERING LOCUS C(FLC)reactivation,what role RNA methylation plays in vernalization-and photoperiod-induced flowering,how methylation participates simultaneously in both vernalization-and photoperiod-induced flowering,the heritability of methylation memory under the vernalization/photoperiod pathway,and whether and how methylation replaces vernalization/photoinduction to regulate flowering.Our review provides insight about the crosstalk among the genetic control of the flowering gene network,methylation(methyltransferases/demethylases)and external signals(cold,light,sRNA and phytohormones)in vernalization and photoperiod pathways.The existing evidence that RNA methylation may play a potential regulatory role in vernalization-and photoperiod-induced flowering has been gathered and represented for the first time.This review speculates about and discusses the possibility of substituting methylation for vernalization and photoinduction to promote flowering.Current evidence is utilized to discuss the possibility of future methylation reagents becoming flowering regulators at the molecular level.

Molecular underpinnings for microbial extracellular electron transfer during biogeochemical cycling of earth elements

Microbial extracellular electron transfer(EET) is electron exchanges between the quinol/quinone pools in microbial cytoplasmic membrane and extracellular substrates. Microorganisms with EET capabilities are widespread in Earth hydrosphere, such as sediments of rivers, lakes and oceans, where they play crucial roles in biogeochemical cycling of key elements, including carbon,nitrogen, sulfur, iron and manganese. Over the past 12 years, significant progress has been made in mechanistic understanding of microbial EET at the molecular level. In this review, we focus on the molecular mechanisms underlying the microbial ability for extracellular redox transformation of iron, direct interspecies electron transfer as well as long distance electron transfer mediated by the cable bacteria in the hydrosphere.