TaTIP41 and TaTAP46 positively regulate drought tolerance in wheat by inhibiting PP2A activity

Drought is a major environmental stress limiting global wheat(Triticum aestivum)production.Exploring drought tolerance genes is important for improving drought adaptation in this crop.Here,we cloned and characterized TaTIP41,a novel drought tolerance gene in wheat.TaTIP41 is a putative conserved component of target of rapamycin(TOR)signaling,and the Ta TIP41 homoeologs were expressed in response to drought stress and abscisic acid(ABA).The overexpression of Ta TIP41 enhanced drought tolerance and the ABA response,including ABA-induced stomatal closure,while its downregulation using RNA interference(RNAi)had the opposite effect.Furthermore,Ta TIP41 physically interacted with TaTAP46,another conserved component of TOR signaling.Like TaTIP41,TaTAP46 positively regulated drought tolerance.Furthermore,TaTIP41 and TaTAP46 interacted with type-2A protein phosphatase(PP2A)catalytic subunits,such as TaPP2A-2,and inhibited their enzymatic activities.Silencing TaPP2A-2 improved drought tolerance in wheat.Together,our findings provide new insights into the roles of TaTIP41 and TaTAP46 in the drought tolerance and ABA response in wheat,and their potential application in improving wheat environmental adaptability.

5-Methylcytosine RNA Methylation in Arabidopsis Thaliana

5-Methylcytosine （m^5C） is a well-characterized DNA modification, and is also predominantly reported in abundant non-coding RNAs in both prokaryotes and eukaryotes. However, the distribution and biological functions of m^5C in plant mRNAs remain largely unknown. Here, we report transcriptome-wide profiling of RNA m^5C in Arabidopsis thaliana by applying m^5C RNA immunoprecipitation followed by a deep- sequencing approach （m^5C-RIP-seq）. LC-MS/MS and dot blot analyses reveal a dynamic pattern of m^5C mRNA modification in various tissues and at different developmental stages, m^5C-RIP-seq analysis identified 6045 m^5C peaks in 4465 expressed genes in young seedlings. We found that m^5C is enriched in coding sequences with two peaks located immediately after start codons and before stop codons, and is associated with mRNAs with low translation activity. We further demonstrated that an RNA （cytosine-5）-methyl- transferase, tRNA-specific methyltransferase 4B （TRM4B）, exhibits m^5C RNA methyltransferase activity. Mutations in TRM4B display defects in root development and decreased m^5C peaks. TRM4B affects the transcript levels of the genes involved in root development, which is positively correlated with their mRNA stability and m^5C levels. Our results suggest that m^5C in mRNA is a new epitranscriptome marker inArabidopsis, and that regulation of this modification is an integral part of gene regulatory networks underlying plant development.

Adenine Methylation： New Epigenetic Marker ol DNA and mRNA

Methylation on the sixth position of the purine ring of adenine has been detected in both mRNA （N^6-methyladenosine [m^6A]） and DNA （N^6-methyladenine [6mA]） in eukaryotes. Recent studies suggest that m^6A plays regulatory functions and is essential for Arabidopsis development, and 6mA is associated with gene expression in plants.

The N^6-adenine methylation in yeast genome profiled by single-molecule technology

The most common and abundant DNA modification is 5-methylcytosine（5mC）,which has been well-established as an epigenetic mark regulating gene expression in eukaryotes（Jones,2012）.Another DNA modification N^6-methyldeoxyadenosine（6mA）,previously reported as a widespread DNA methylation in prokaryotes.

PRMT6 physically associates with nuclear factor Y to regulate photoperiodic flowering in Arabidopsis

The timing of floral transition is critical for reproductive success in flowering plants.In long-day(LD)plant Arabidopsis,the floral regulator gene FLOWERING LOCUS T(FT)is a major component of the mobile florigen.FT expression is rhythmically activated by CONSTANS(CO),and specifically accumu-lated at dusk of LDs.However;the underlying mechanism of adequate regulation of FT transcription in response to day-length cues to warrant flowering time still remains to be investigated.Here,we identify a homolog of human protein arginine methyltransferases 6(HsPRMT6)in Arabidopsis,and confirm AtPRMT6 physically interacts with three positive regulators of flowering Nuclear Factors YC3(NF-YC3),NF-YC9,and NF-YB3.Further investigations find that AtPRMT6 and its encoding protein accumulate at dusk of LDs.PRMT6-mediated H3 R2me2a modification enhances the promotion of NF-YCs on FT transcription in response to inductive LD signals.Moreover,AtPRMT6 and its homologues proteins AtPRMT4a and AtPRMT4b coordinately inhibit the expression of FLOWERING LOCUS C,a suppressor of FT.Taken together,our study reveals the role of arginine methylation in photoperiodic pathway and how the PRMT6-mediating H3R2me2a system interacts with NF-CO module to dynamically control FT expression and facilitate flowering time.

Correction to:PRMT6 physically associates with nuclear factor Y to regulate photoperiodic flowering in Arabidopsis

In this artice Figs.2 and 3 were wrongly numbered;Fig.2 should have been Fig.3 and vice versa as shown below.Moreover,the Fig.3 indications have been revised as shown:the sentence"Next,two transfer DNA(T-DNA)insertion single-mutant prmt6-1(Sail 385_A06)and prmt6-2(Salk 151679C)(Figs.2A;S3)..'has been revised as“Next,two transfer DNA(T-DNA)inser-tion single-mutant prmt6-1(Sail 385_A06)and prmt6-2(Salk 151679C)(Figs.3A;S3..".