Transcriptome analysis of purple pigment formation in Colocasia esculenta

Taro(Colocasia esculenta(L.)Schott)is an important crop in Africa,Southeast Asia,and subtropics and is used as a food and medicine.The purple color pigmentation is an appealing character in taro.We sampled taro corms of the cultivar‘Lipu Taro’at four developmental stages,including LPYS1(without purple pigment,50 days of development(DOD)),LPYS2(very few purple pigments,75 DOD),LPYS3(moderate purple pigments,115 DOD)and LPYS4(high purple pigments,205 DOD).The purpose of our study was to identify the key genes underpinning the purple pigmentation in taro based on RNA-sequencing.Through RNA-Seq,6453 differentially expressed transcripts(DETs)were identified between purple and non-purple pigmented samples.We identified 41 and 12 flavonoid and anthocyanin related DETs transcripts,respectively.These DETs were upregulated at LPYS2,LPYS3,and LPYS4 as compared to LPYS1,indicating their positive contribution to the color formation in taro.Moreover,we identified several DETs encoding for transcription factors,including MYB and bHLH,known to be major regulators of structural genes involved in the flavonoid-anthocyanin pathway.Finally,we reported several plant hormones(ethylene,auxin,gibberellin,jasmonic acid,and cytokinin)related DETs,which are predicted to play important roles in the corm coloration.Different regulation of transcripts representing the flavonoid-anthocyanin biosynthesis pathway,plant hormone transduction pathway,and transcription factors may have key roles in purple pigmentation in taro.Our findings will facilitate future research on improving the quality and appeal of taro.

基于正交实验的赤苍藤组培快繁体系建立

以赤苍藤(Erythropalum scandens)带芽点的半木质化枝条为材料建立赤苍藤组培快繁体系,研究外植体灭菌条件,通过正交实验,设计不同植物生长调节剂组合对赤苍藤愈伤组织诱导、愈伤组织分化、生根壮苗及移栽驯化的影响。结果表明,赤苍藤外植体消毒最佳方法是以体积浓度为75%乙醇浸泡60秒后,再以质量浓度为0.1%HgCl_2消毒10分钟,成功率为48.89%;叶片愈伤组织诱导的最佳培养基为MS+0.5 mg·L^(-1) 6-BA+1.0 mg·L^(-1) 2,4-D+1.0 mg·L^(-1) IBA,培养30天,诱导率达71.11%,且绿色紧密;茎段诱导愈伤组织的最佳培养基为MS+1.0 mg·L^(-1) 6-BA+0.5 mg·L^(-1) 2,4-D+1.0 mg·L^(-1) IBA,培养30天,诱导率为70.00%,且绿色紧密;诱导愈伤组织增殖以及分化的最佳培养基为MS+2.0mg·L^(-1) 6-BA+0.5mg·L^(-1)TDZ+1.0 mg·L^(-1) IBA,芽分化率达98.89%,增殖系数为3.33;生根最佳培养基为MS+1.5 mg·L^(-1) 6-BA+0.5 mg·L^(-1) IBA,生根率为100%,平均生根数为2.2条;生根苗在小颗粒泥炭土中成活率达88.89%。该研究建立了赤苍藤组培快繁体系,为赤苍藤优质种苗生产奠定了良好基础。

GmDFB1,an ARM-repeat superfamily protein,regulates floral organ identity through repressing siRNA-and miRNA-mediated gene silencing in soybean

The development of flowers in soybean(Glycine max)is essential for determining the yield potential of the plant.Gene silencing pathways are involved in modulating flower development,but their full elucidation is still incomplete.Here,we conducted a forward genetic screen and identified an abnormal flower mutant,deformed floral bud1-1(Gmdfb1-1),in soybean.We mapped and identified the causal gene,which encodes a member of the armadillo(ARM)-repeat superfamily.Using small RNA sequencing(sRNA-seq),we found an abnormal accumulation of small interfering RNAs(si RNAs)and microRNA(miRNAs)in the Gmdfb1 mutants.We further demonstrated that GmDFB1 interacts with the RNA exosome cofactor SUPER KILLER7(Gm SKI7).Additionally,GmDFB1 interacts with the PIWI domain of ARGONAUTE 1(GmAGO1)to inhibit the cleavage efficiency on the target genes of s RNAs.The enhanced gene silencing mediated by siRNA and miRNA in the Gmdfb1 mutants leads to the downregulation of their target genes associated with flower development.This study revealed the crucial role of GmDFB1 in regulating floral organ identity in soybean probably by participating in two distinct gene silencing pathways.

Significant influence of trace Li on the mechanical properties, corrosion behavior, and antibacterial properties of biodegradable Zn–4Cu alloys

In this work,trace Li was introduced to strengthen Zn–4Cu alloys.The results indicated that trace amounts of Li contributed to a significant increase in strength,resulting in an acceptable loss of elongation at fracture.Additionally,Li in the form of LiZn_(4) led to more intensive galvanic corrosion,which accelerated the early corrosion rate.The release of a large amount of Zn^(2+),caused by the addition of Li,affected the phase composition of the main Zn-containing corrosion products.Moreover,the inhibition effect of the alloy on Staphylococcus aureus(S.aureus)was enhanced by the addition of 0.02 wt.%Li.

Engineering single–atom active sites anchored covalent organic frameworks for efficient metallaphotoredox C-N cross–coupling reactions

Photoredox catalysis has become an indispensable solution for the synthesis of small organic molecules.However,the precise construction of single-atomic active sites not only determines the catalytic performance,but also avails the understanding of structure–activity relationship.Herein,we develop a facile approach to immobilize single-atom Ni sites anchored porous covalent organic framework(COF)by use of 4,4',4''-(1,3,5-triazine-2,4,6-triyl)trianiline and 2,6-diformylpyridine(Ni SAS/TD-COF).Ni SAS/TDCOF catalyst achieves excellent catalytic performance in visible-light-driven catalytic carbon–nitrogen cross-coupling reaction between aryl bromides and amines under mild conditions.The reaction provides amine products in excellent yields(71%–97%)with a wide range of substrates,including aryl and heteroaryl bromides with electron-deficient,electron-rich and neutral groups.Notably,Ni SAS/TD-COF could be recovered from the reaction mixture,corresponding to the negligible loss of photoredox performance after several cycles.This work provides a promising opportunity upon rational design of single-atomic active sites on COFs and the fundamental insight of photoredox mechanism for sustainable organic transformation.