OsNRAMP2 facilitates Cd efflux from vacuoles and contributes to the difference in grain Cd accumulation between japonica and indica rice

Cadmium(Cd)accumulation in rice grain is of health concern.Identifying genes involved in grain Cd accumulation and performing molecular breeding may reduce it.In this study,knockout of OsNRAMP2,a member of the NRAMP family,reduced grain Cd concentrations by more than 38%,and overexpressing OsNRAMP2 increased grain Cd concentrations by more than 50%.Physiological experiments showed that OsNRAMP2 facilitated Cd translocation from root to shoot by positively regulating Cd efflux from the vacuoles.At filling stage,OsNRAMP2 was highly expressed in all tissues except for husk,suggesting its role in Cd remobilization.Changes in OsNRAMP2 expression affected the concentrations of Fe,Mn,Zn,and Cu in grain and also affected rice growth.Phylogenetic analysis showed that the distribution of OsNRAMP2 haplotypes between japonica and indica was different.Among the four haplotypes of OsNRAMP2,Hap 1,with a 6-bp nucleotide insertion in exon 1,had grain Cd concentration at least 45.3%lower than any of the other three haplotypes.Almost all(99.3%)japonica accessions but rare indica accessions(4.44%)from the 3K sequenced rice genomes carry Hap 1 of OsNRAMP2.Our study sheds light on the molecular mechanism of grain Cd accumulation and provides a promising target for low-Cd rice breeding.

COMBINING COGNITIVE AND CORPUS LINGUISTIC APPROACHES IN LANGUAGE RESEARCH AND TEACHING:THEORETICAL GROUNDING,PRACTICES,AND CHALLENGES

Cognitive Linguistics and corpus linguistics have emerged as arguably the two most influential contemporary linguistic approaches in applied linguistics,as evidenced by an increasing number of studies using either one or the other approach.However,due perhaps to the surface differences between them,there has not been much research on how the two approaches can be combined to make language research more valid and language teaching more effective.This paper discusses the need and existing effort to integrate the two linguistic approaches in language research and teaching.The paper first explores the theoretical grounds and rationales for combining them.It then describes how such a combined approach may enhance(1)the validity and reliability of research on language use and(2)the effectiveness of language learning/teaching.Finally,the paper discusses the challenges and future directions of employing such a combined approach.