Mixing trait-based corn(Zea mays L.)cultivars increases yield through pollination synchronization and increased cross-fertilization

Abiotic stress such as high temperature at flowering is one of many conditions reducing yield of corn(Zea mays L.).Mixing corn cultivars with diverse functional traits increases within-crop diversity and provides a potential means of mitigating yield losses under stress conditions.We conducted a three-year field study to investigate the effects of cultivar mixtures on kernel setting rate,pollen sources,and yield.This study consisted of six treatments,including two high temperature-tolerant(HTT)monocrops of WK702 and DH701,two high temperature-sensitive(HTS)monocrops of DH605 and DH662,and two HTT–HTS mixtures of WK702-DH605 and DH701-DH662.The anthesis–silking interval(ASI)was 0.9–1.6 days shorter in mixtures than in monocrops.Kernel setting rate was increased in mixtures(86.4%–88.7%)compared with those in monocrops(74.7%–84.1%)as a result of synchrony and complementarity of pollination.Grain yields of the HTT–HTS mixtures increased by 13.3%–18.7%,equivalent to 1169 to1605 kg ha^(-1),in comparison with HTS corn monocrops.The results of SSR markers showed that crossfertilization percentage in corn cultivar mixtures ranged from 29.3%to 47.8%,partially explaining yield improvement.Land equivalent ratio(LER)was 1.12 for corn mixtures and the partial land equivalent ratio(e.g.,>0.5)showed the complementary benefits in corn mixtures.The results indicated that mixing corn cultivars with diverse flowering and drought-tolerance traits increased yields via pollination synchrony.

High-quality draft genome sequence of Streptomyces agglomeratus 5-1-8 with strong anti-MRSA ability, isolated from the frozen soil of Tibet in China

Streptomyces agglomeratus 5-1-8 with strong anti methicillin-resistant Staphylococcus aureus(MRSA)ability,isolated from the frozen soil of Tibet in China,has a strong ability to kill the multi-drugs-resistant MRSA.To identify the second-ary metabolism ability of this strain,we describe here the phenotypic characteristics of this strain,along with its high-quality draft genome sequence,its annotation,and analysis.The 7.1M draft genome encodes 6,284 putative open reading frames(ORFs),of which 4,416 ORFs were assigned with clusters of orthologous genes(COG)categories.Also,65 t RNA genes and 24 r RNA operons were identified.The genome contains 12 gene clusters involved in antibiotics production and 1 gene cluster involved in anticancer-compounds production;4 gene clusters belong to polyketides and nonribosomal peptides,1gene cluster belong to the butyrolactone,4 gene clusters belong to the bacteriocin or lantipeptide,and 3 gene clusters belong to the others.This genome-sequence data will facilitate efforts to probe the potential of new antibiotics to kill multidrugs-resistant MRSA.

Downregulated lncRNA DRAIC enhances the radiotherapy sensitivity of human HCC cell line HepG2 by targeting miR-223-3p

Objective This study aims to investigate the effects of the long noncoding RNA(lncRNA)DRAIC on the proliferation,apoptosis,and radiosensitivity of hepatocellular carcinoma(HCC)cells and the molecular mechanisms involved.Methods Cancer tissues and their corresponding adjacent tissues from 30 patients with HCC were collected,and the expression levels of DRAIC and miR-223-3p were detected via RT-q PCR.DRAIC interference and miR-223-3p overexpression vectors were transfected into HepG2 cells.In addition,DRAIC and miR-223-3p interference vectors were co-transfected into HepG2 cells.The constructed cells were irradiated at 4 Gy.Cell colony formation assay,MTT assay,and flow cytometry were performed to detect the radiosensitivity,proliferation inhibition rate,and apoptosis rate of HepG2 cells,respectively.Dual luciferase reporter gene assay was performed to detect the targeted regulation of DRAIC on miR-223-3p expression.Results The expression level of DRAIC in HCC tissues was higher than that in paracancer tissues,whereas the expression level of miR-223-3p was lower in HCC tissues than that in paracancer tissues(P<0.05).Inhibition of DRAIC expression or overexpression of miR-223-3p increased the proliferation inhibition and apoptosis rates of HepG2 cells(P<0.05).After irradiation,cell survival fraction decreased and cell proliferation inhibition and apoptosis rates increased(P<0.05).DRAIC targeted the regulation of miR-223-3p expression,and interference of miR-223-3p expression reversed the effects of inhibiting DRAIC expression on the proliferation,apoptosis,and radiosensitivity of HepG2 cells.Conclusion Inhibition of DRAIC expression can inhibit the proliferation of HepG2 cells,promote cell apoptosis,and enhance the radiosensitivity of cells via upregulation of miR-223-3p.

腐植酸在鱼腥藻上对纳米氧化锌和Zn^2＋的毒性影响

本研究探讨腐植酸（HA）对纳米氧化锌和Zn2＋毒性的影响。通过脉冲振幅调制荧光仪测定对鱼腥藻典型叶绿素荧光参数。结果表明，当纳米氧化锌与Zn2＋的EC50（最大效应浓度50％）分别为0．74±0．01和0．3±0．01mg／L时能抑制鱼腥藻生长。当HA为3mg／L时，纳米氧化锌EC50浓度增加到1．15±0．04mg／L，