Transcriptome and morphological analyses of double flower formation in Dianthus chinensis

The double flower developmental process is regulated via a complex transcriptional regulatory network.To understand this highly dynamic and complex developmental process of Dianthus spp.,we performed a comparative analysis of floral morphology and transcriptome dynamics in simple flowers and double flowers.We found that the primordium of double flowers of‘X’was larger in size compared to that of simple flowers of‘L’in Dianthus chinensis.RNA-seq and Weighted Gene Co-expression Network Analysis(WGCNA)during flower development,identified stage-specific gene network modules.Expression analysis by RNA-seq indicated that a group of genes related to floral meristem identity,primordia position and polarity were highly expressed in double flowers genotypes compared to simple flowers genotypes,suggesting their roles in double-petal formation.A total of 21 DEGs related to petal number were identified between simple and double flowers.The experiments of in situ hybridization revealed that DcaAP2L,DcaLFY and DcaUFO genes were expressed in the intra-sepal boundary and petal boundary.We proposed a potential transcriptional regulatory network for simple and double flower development.This study provides novel insights into the molecular mechanism underlying double flower formation in Dianthus spp.

A high-quality Bougainvillea genome provides new insights into evolutionary history and pigment biosynthetic pathways in the Caryophyllales

Bougainvillea is a perennial ornamental shrub that is highly regarded in ornamental horticulture around the world.However,the absence of genome data limits our understanding of the pathways involved in bract coloration and breeding.Here,we report a chromosome-level assembly of the giga-genome of Bougainvillea×buttiana‘Mrs Butt’,a cultivar thought to be the origin of many other Bougainvillea cultivars.The assembled genome is∼5 Gb with a scaffold N50 of 151756278 bp and contains 86572 genes which have undergone recent whole-genome duplication.We confirmed that multiple rounds of whole-genome multiplication have occurred in the evolutionary history of the Caryophyllales,reconstructed the relationship in the Caryophyllales at whole genome level,and found discordance between species and gene trees as the result of complex introgression events.We investigated betalain and anthocyanin biosynthetic pathways and found instances of independent evolutionary innovations in the nine different Caryophyllales species.To explore the potential formation mechanism of diverse bract colors in Bougainvillea,we analyzed the genes involved in betalain and anthocyanin biosynthesis and found extremely low expression of ANS and DFR genes in all cultivars,which may limit anthocyanin biosynthesis.Our findings indicate that the expression pattern of the betalain biosynthetic pathway did not directly correlate with bract color,and a higher expression level in the betalain biosynthetic pathway is required for colored bracts.This improved understanding of the correlation between gene expression and bract color allows plant breeding outcomes to be predicted with greater certainty.

Construction of a few-layer g-C_3N_4/α-MoO_3 nanoneedles all-solid-state Z-scheme photocatalytic system for photocatalytic degradation

The suppression of the recombination of electrons and holes(e–h) and the enhancement of the light absorption of semiconductors are two key points toward efficient photocatalytic degradation.Here,we report a few-layer g-C_3N_4/α-MoO_3 nanoneedles(flg-C_3N_4/α-MoO_3 NNs) all-solid-state Z-scheme mechanism photocatalyst synthesized via a typical hydrothermal method in a controlled manner.The recombination of the photo-induced e–h pairs could be effectively restrained by the Z-scheme passageway between the flg-C_3N_4 and α-MoO_3 NNs in the composite,which could also promise a high redox ability to degrade pollutants.And it became possible for the prepared photocatalyst to absorb light in a wide range of wavelengths.The detailed mechanism was studied by electron spin-resonance spectroscopy(ESR).The low-dimensional nanostructure of the two constituents(α-MoO_3 NNs with one-dimensional structure and flg-C_3N_4 with two-dimensional structure) endowed the composite with varieties of excellent physicochemical properties,which facilitated the transfer and diffusion of the photoelectrons and increased the specific surface area and the active sites.The 10 wt% flg-C_3N_4/α-MoO_3 NNs showed the best photocatalytic performance toward RhB degradation,the rate of which was 71.86%,～2.6 times higher than that ofα-MoO_3 NNs.

Pollutant emissions,energy consumption and economic development in China:Evidence from dynamic panel data

This study investigates the relationship among pollutant emissions,energy consumption and economic development in China during the period 1982-2007 by using a one-step GMM-system model under a multivariable panel VAR framework,controlling for capital stock and labor force.Regarding the data for all 28 provinces as a whole,we find that there is a unidirectional positive relationship running from pollutant emission to economic development and a unidirectional negative relationship between pollutant emission and energy consumption.Based on traditional economic planning,the panel data of28 provinces are divided into two cross-province groups.It is discovered that in the eastern coastal region of China,there is only a unidirectional positive causal relationship leading from economic development to pollutant emission;while in the central and western regions,there are the unidirectional Granger causal relationships between pollutant emission and energy consumption,as well as between pollutant emission and economic development.There is also a unique unidirectional causal relationship running from economic development to energy consumption,which does not appear in the eastem coastal region or in China as a whole.

Review Study on the Accumulation and Release of Trace Metal Elements on Aluminum Containing Sediments in Drinking Water Distribution System

Accumulation and releasing of trace metal elements on aluminum containing sediments of inner drinking water pipe is discussed,as studied from five variations effecting:raw water quality,chemical reagents,solution pH and drinking water flow condition.In order to decrease the release of trace metal elements,and to ensure the pipe operation and human safety,water quality adjustment is suggested to avoid aluminum containing sediments formation in drinking distribution system.The maximum amounts of accumulation of common trace metal elements are given.Future trends of development in this field are also proposed.

The genomic and bulked segregant analysis of Curcuma alismatifolia revealed its diverse bract pigmentation

Compared with most flowers where the showy part comprises specialized leaves(petals)directly subtending the reproductive structures,most Zingiberaceae species produce showy“flowers”through modifications of leaves(bracts)subtending the true flowers throughout an inflorescence.Curcuma alismatifolia,belonging to the Zingiberaceae family,a plant species originating from Southeast Asia,has become increasingly popular in the flower market worldwide because of its varied and esthetically pleasing bracts produced in different cultivars.Here,we present the chromosome-scale genome assembly of C.alismatifolia“Chiang Mai Pink”and explore the underlying mechanisms of bract pigmentation.Comparative genomic analysis revealed C.alismatifolia contains a residual signal of whole-genome duplication.Duplicated genes,including pigment-related genes,exhibit functional and structural differentiation resulting in diverse bract colors among C.alismatifolia cultivars.In addition,we identified the key genes that produce different colored bracts in C.alismatifolia,such as F3′5'H,DFR,ANS and several transcription factors for anthocyanin synthesis,as well as chlH and CAO in the chlorophyll synthesis pathway by conducting transcriptomic analysis,bulked segregant analysis using both DNA and RNA data,and population genomic analysis.This work provides data for understanding the mechanism of bract pigmentation and will accelerate breeding in developing novel cultivars with richly colored bracts in C.alismatifolia and related species.It is also important to understand the variation in the evolution of the Zingiberaceae family.