Overexpression of CmSOS1 confers waterlogging tolerance in Chrysanthemum

正Plants experiencing hypoxia (a shortage of oxygen)are unable to maintain aerobic respiration, which leads to an energy and carbohydrate deficit. The pervasive and rapid accumulation of ethylene is an early and reliable response to hypoxic stress(Sasidharan and Voesenek 2015), producing an uptick in the accumulation of reactive oxygen species (ROS).This in turn triggers apoptosis in root cortex cells,eventually leading to the formation of lysigenous aerenchyma, a tissue from which ethylene is readily     

The embryo rescue derived intergeneric hybrid between chrysanthemum and Ajania przewalskii shows enhanced cold tolerance

Five intergeneric hybrids between the chrysanthemum cultivar ‘Zhongshanjingui’ (as female) and Ajania przewalskii (as male) were obtained with the help of embryo culture. While ‘Zhongshanjingui’ bears a standard anemone type flower and A. przewalskii a non-anemone type one, the inflorescence type of the hybrids varied. The diameter of the hybrids’ flowers was intermediate between those of the parents. The chromosome number of the hybrids was 2n = 45, of which GISH analysis was able to establish that 27 were inherited from ‘Zhongshanjingui’ and the other 18 from A. przewalskii. A combination of various assays was used to show that the cold tolerance of the hybrids was equivalent to that of the highly tolerant A. przewalskii parent. Enhanced cold tolerance was correlated with an increase in free proline and a decrease in malondialdehyde content.     

A porcine gene, PBK, differentially expressed in the longissimus muscle from Meishan and Large White pig

An investigation of differences in gene expression in the longissimus muscle of Meishan and Large White pigs was undertaken, using the mRNA display technique. A fragment of one differentially expressed gene was isolated and sequenced, whereupon the complete cDNA sequence was then obtained by using the rapid amplification of cDNA ends (RACE). The nucleotide sequence of the gene is not related to any known porcine gene. Sequence analysis revealed that the open reading frame of this gene encodes a protein with 322 amino acids, thus displaying high sequence identity with the PDZ binding kinase (PBK) of eleven other animal species - dog, horse, cattle, human, chimpanzee, crab-eating macaque, rhesus monkey, rat, mouse, gray short-tailed opossum and platypus, so it can be defined as the porcine PBK gene. This gene was finally assigned GeneID:100141310. Phylogenetic tree analysis revealed that the swine PBK gene has a closer genetic relationship with the PBK gene of platypus. Gene expression analysis of eight tissues of a Meishan x Large White cross showed that the porcine PBK gene is differentially expressed in various tissues. Our experiment established the primary foundation for further research on this gene.     

菊属与蒿属植物苗期抗蚜虫性鉴定

为发掘对蚜虫有抗性的菊花近缘种属植物,对11份菊属及蒿属植物苗期进行了田间和室内抗蚜虫性鉴定。结果发现:在田间鉴定条件下,随着平均蚜害指数(I*)值的升高,蚜虫抗性等级逐渐降低,其中:黄金艾蒿、黄蒿、香蒿的I*值为0.00,属于免疫性;牡蒿的I*值为0.13,属于高抗性;大岛野路菊的I*值为0.25,属于抗性;异色菊的I*值为0.37,属于中抗性;那贺川野菊、龙脑菊的I*值为0.51—0.75,属于感性;泡黄金菊、紫花野菊、菊花脑的I*值>0.75,属于高感性;在室内鉴定条件下,不同材料对蚜虫的抗性表现出很大差异,根据繁殖倍率的不同,11份材料分为5个抗性等级,其中黄金艾蒿、牡蒿、黄蒿、香蒿繁殖倍率为0.00,属于极高抗性;大岛野路菊繁殖倍率为5.86,属于中抗性;异色菊、那贺川野菊、龙脑菊繁殖倍率为7—10,属于低抗性;泡黄金菊、紫花野菊、菊花脑繁殖倍率>10,属于无抗性。综合分析表明:田间鉴定与室内鉴定结果基本一致,其中黄金艾蒿、黄蒿等8份材料田间和室内鉴定结果无差别;牡蒿田间鉴定表现为高抗性,而室内鉴定表现为极高抗性;大岛野路菊田间鉴定表现为抗性,而室内鉴定表现为中抗性;异色菊田间鉴定表现为中抗性,而室内鉴定表现为低抗性。黄金艾蒿、黄蒿、牡蒿、香蒿、大岛野路菊对蚜虫表现良好抗性,可用于栽培菊花抗蚜性遗传改良。     

Identification of favorable SNP alleles and candidate genes responsible for inflorescence-related traits via GWAS in chrysanthemum

Key message

81 SNPs were identified for three inflorescence-related traits, in which 15 were highly favorable. Two dCAPS markers were developed for future MAS breeding, and six candidate genes were predicted.

Abstract

Chrysanthemum is a leading ornamental species worldwide and demonstrates a wealth of morphological variation. Knowledge about the genetic basis of its phenotypic variation for key horticultural traits can contribute to its effective management and genetic improvement. In this study, we conducted a genome-wide association study (GWAS) based on two years of phenotype data and a set of 92,617 single nucleotide polymorphisms (SNPs) using a panel of 107 diverse cut chrysanthemums to dissect the genetic control of three inflorescence-related traits. A total of 81 SNPs were significantly associated with the three inflorescence-related traits (capitulum diameter, number of ray florets and flowering time) in at least one environment, with an individual allele explaining 22.72–38.67% of the phenotypic variation. Fifteen highly favorable alleles were identified for the three target traits by computing the phenotypic effect values for the stable associations detected in 2 year-long trials at each locus. Dosage pyramiding effects of the highly favorable SNP alleles and significant linear correlations between highly favorable allele numbers and corresponding phenotypic performance were observed. Two highly favorable SNP alleles correlating to flowering time and capitulum diameter were converted to derived cleaved amplified polymorphic sequence (dCAPS) markers to facilitate future breeding. Finally, six putative candidate genes were identified that contribute to flowering time and capitulum diameter. These results serve as a foundation for analyzing the genetic mechanisms underlying important horticultural traits and provide valuable insights into molecular marker-assisted selection (MAS) in chrysanthemum breeding programs.

     

Inhibitory neuromuscular transmission mediated by the P2Y1 purinergic receptor in guinea pig small intestine

ATP is a putative inhibitory neurotransmitter responsible for inhibitory junction potentials (IJPs) at neuromuscular junctions (IJPs) in the intestine. This study tested the hypothesis that the purinergic P2Y(1) receptor subtype mediates the IJPs. IJPs were evoked by focal electrical stimulation in the myenteric plexus and recorded with "sharp" intracellular microelectrodes in the circular muscle coat. Stimulation evoked three categories of IJPs: 1) purely purinergic IJPs, 2) partially purinergic IJPs, and 3) nonpurinergic IJPs. Purely purinergic IJPs were suppressed by the selective P2Y(1) purinergic receptor antagonist MRS2179. Purely purinergic IJPs comprised 26% of the IJPs. Partially purinergic IJPs (72% of the IJPs) consisted of a component that was abolished by MRS2179 and a second unaffected component. The MRS2179-insensitive component was suppressed or abolished by inhibition of formation of nitric oxide by N(omega)-nitro-l-arginine methyl ester (l-NAME) in some, but not all, IJPs. An unidentified neurotransmitter, different from nitric oxide, mediated the second component in these cases. Nonpurinergic IJPs were a small third category (4%) of IJPs that were abolished by l-NAME and unaffected by MRS2179. Exogenous application of ATP evoked IJP-like hyperpolarizing responses, which were blocked by MRS2179. Application of apamin, which suppresses opening of small-conductance Ca(2+)-operated K(+) channels in the muscle, decreased the amplitude of the purinergic IJPs and the amplitude of IJP-like responses to ATP. The results support ATP as a neurotransmitter for IJPs in the intestine and are consistent with the hypothesis that the P2Y(1) purinergic receptor subtype mediates the action of ATP.     

东海赤潮高发区沉积物中叶绿素的分析

研究分析了2002年8～9月“赤潮973”航次所采集的沉积物中叶绿素a及其降解产物脱镁叶绿酸含量与分布．结果表明。叶绿素a和脱镁叶绿酸是同源的;随深度增加叶绿素a和脱镁叶绿酸的含量呈递减趋势,到一定深度后含量不再变化。个别站位叶绿素a和脱镁叶绿酸的垂直分布出现了许多小突跃,可能是由生物扰动引起;表层沉积物(0～0．5cm)中的叶绿素a和脱镁叶绿酸的变化幅度分别为0．14～1．17和0．83～5．58μg·g-1。平均值分别为0．54和2．45μg·g-1;并初步探讨水深(光强)、盐度、温度、含水量对叶绿素水平分布的影响;脱镁叶绿酸作为叶绿素的主要降解产物,到一定深度后,成为叶绿素的主要存在形式,约占80％～90％;由于水温的不同,夏季沉积物中的叶绿素a和脱镁叶绿酸含量是春季的3倍之多;比较了上层水柱中的叶绿素和沉积物中的叶绿素的相对含量,平均而言,沉积物中叶绿素占上层水柱中叶绿素的31％．