Strigolactones modulate cotton fiber elongation and secondary cell wall thickening

Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes of plant growth and development,although the functions of SL in fiber development remain largely unknown.Here,we found that the endogenous SLs were significantly higher in fibers at 20 days post-anthesis(DPA).Exogenous SLs significantly increased fiber length and cell wall thickness.Furthermore,we cloned three key SL biosynthetic genes,namely GhD27,GhMAX3,and GhMAX4,which were highly expressed in fibers,and subcellular localization analyses revealed that GhD27,GhMAX3,and GhMAX4 were localized in the chloroplast.The exogenous expression of GhD27,GhMAX3,and GhMAX4 complemented the physiological phenotypes of d27,max3,and max4 mutations in Arabidopsis,respectively.Knockdown of GhD27,GhMAX3,and GhMAX4 in cotton resulted in increased numbers of axillary buds and leaves,reduced fiber length,and significantly reduced fiber thickness.These findings revealed that SLs participate in plant growth,fiber elongation,and secondary cell wall formation in cotton.These results provide new and effective genetic resources for improving cotton fiber yield and plant architecture.

Application of super-resolution fluorescence microscopy in hematologic malignancies

Hematologic malignancies are one of the most common malignant tumors caused by the clonal proliferation and differentiation of hematopoietic and lymphoid stem cells.The examination of bone marrow cells combined with immunodeficiency typing is of great significance to the diagnostic type,treatment and prognosis of hematologic malignancies.Super-resolution fluorescence microscopy(SRM)is a special kind of optical microscopy technology,which breaks the resolution limit and was awarded the Nobel Prize in Chemistry in 2014.With the development of SRM,many related technologies have been applied to the diagnosis and treatment of clinical diseases.It was reported that a major type of SRM technique,single molecule localization microscopy(SMLM),is more sensitive than flow cytometry(FC)in detecting cell membrane antigens'expression,thus enabling better chances in detecting antigens on hematopoietic cells than traditional analytic tools.Furthermore,SRM may be applied to clinical pathology and may guide precision medicine and personalized medicine for clone hematopoietic cell diseases.In this paper,we mainly discuss the application of SRM in clone hematological malignancies.

Upgraded durian genome reveals the role of chromosome reshuffling during ancestral karyotype evolution,lignin biosynthesis regulation,and stress tolerance

Durian(Durio zibethinus)is a tropical fruit that has a unique flavor and aroma.It occupies a significant phylogenetic position within the Malvaceae family.Extant core-eudicot plants are reported to share seven ancestral karyotypes that have undergone reshuffling,resulting in an abundant genomic diversity.However,the ancestral karyotypes of the Malvaceae family,as well as the evolution trajectory leading to the28 chromosomes in durian,remain poorly understood.Here,we report the high-quality assembly of the durian genome with comprehensive comparative genomic analyses.By analyzing the collinear blocks between cacao and durian,we inferred 11 Malvaceae ancestral karyotypes.These blocks were present in a single-copy form in cacao and mainly in triplicates in durian,possibly resulting from a recent whole genome triplication(WGT)event that led to hexaploidization of the durian genome around 20(17–24)million years ago.A large proportion of the duplicated genes in durian,such as those involved in the lignin biosynthesis module for phenylpropane biosynthesis,are derived directly from whole genome duplication,which makes it an important force in reshaping its genomic architecture.Transcriptome studies have revealed that genes involved in feruloyl-Co A formations were highly preferentially expressed in fruit peels,indicating that the thorns produced on durian fruit may comprise guaiacyl and syringyl lignins.Among all the analyzed transcription factors(TFs),members of the heat shock factor family(HSF)were the most significantly upregulated under heat stress.All subfamilies of genes encoding heat shock proteins(HSPs)in the durian genome appear to have undergone expansion.The potential interactions between HSF Dzi05.397 and HSPs were examined and experimentally verified.Our study provides a high-quality durian genome and reveals the reshuffling mechanism of ancestral Malvaceae chromosomes to produce the durian genome.We also provide insights into the mechanism underlying lignin biosynthesis and heat stress tolerance.

GhCTSF1,a short PPR protein with a conserved role in chloroplast development and photosynthesis,participates in intron splicing of rpoC1 and ycf3-2 transcripts in cotton

Cotton is one of the most important textile fibers worldwide.As crucial agronomic traits,leaves play an essential role in the growth,disease resistance,fiber quality,and yield of cotton plants.Pentatricopeptide repeat(PPR)proteins are a large family of nuclear-encoded proteins involved in organellar or nuclear RNA metabolism.Using a virus-induced gene silencing assay,we found that cotton plants displayed variegated yellow leaf phenotypes with decreased chlorophyll content when expression of the PPR gene GhCTSF1 was silenced.GhCTSF1 encodes a chloroplast-localized protein that contains only two PPR motifs.Disruption of GhCTSF1 substantially reduces the splicing efficiency of rpoC1 intron 1 and ycf3 intron 2.Loss of function of the GhCTSF1 ortholog EMB1417 causes splicing defects in rpoC1 and ycf3-2,leading to impaired chloroplast structure and decreased photosynthetic rates in Arabidopsis.We also found that GhCTSF1 interacts with two splicing factors,GhCRS2 and GhWTF1.Defects in GhCRS2 and GhWTF1 severely affect intron splicing of rpoC1 and ycf3-2 in cotton,leading to defects in chloroplast development and a reduction in photosynthesis.Our results suggest that GhCTSF1 is specifically required for splicing rpoC1 and ycf3-2 in cooperation with GhCRS2 and GhWTF1.

Genetic-algorithm-based artificial intelligence control of a turbulent boundary layer

An artificial intelligence(AI)open-loop control system is developed to manipulate a turbulent boundary layer(TBL)over a flat plate,with a view to reducing friction drag.The system comprises six synthetic jets,two wall-wire sensors,and genetic algorithm for the unsupervised learning of optimal control law.Each of the synthetic jets through rectangular streamwise slits can be independently controlled in terms of its exit velocity,frequency and actuation phase.Experiments are conducted at a momentum-thickness-based Reynolds number Re_(θ)of 1450.The local drag reduction downstream of the synthetic jets may reach 48%under conventional open-loop control.This local drag reduction rises to 60%,with an extended effective drag reduction area,under the AI control that finds optimized non-uniform forcing.The results point to the significant potential of AI in the control of a TBL given distributed actuation.