Molecular mapping of genomic regions underlying barley yellow dwarf tolerance in cultivated oat (Avena sativa L.)

Barley yellow dwarf (BYD) is one of the most important viral diseases in small grains, including oat (Avena sativa L.). Breeding for BYD tolerance is an effective and efficient means to control the disease. Characterization of major sources of tolerance, and identification of marker and the trait associations, will directly benefit breeding for BYD tolerance. Genomic regions underlying BYD tolerance were mapped and characterized in an oat population consisting of 152 recombinant inbred lines from the cross of 'Ogle' (tolerant)/MAM17-5 (sensitive). Tolerance was evaluated in replicated field trials across 2 years under artificial inoculation with viruliferous aphids harboring BYD virus isolate PAV-IL. Composite interval mapping was used for quantitative trait loci (QTLs) analysis with a framework map consisting of 272 molecular markers. Four QTLs, BYDq1, BYDq2, BYDq3 and BYDq4, for BYD tolerance were identified on linkage groups OM1, 5, 7 and 24, respectively. All but BYDq2 were consistently detected across both years. Significant epistasis was found between some QTLs. The final model including the epistatic effect explained 50.3 to 58.2% of the total phenotypic variation for BYD tolerance. Some QTLs for BYD tolerance were closely linked to QTLs for plant height and days to heading. Potential problems with QTL mapping for BYD tolerance have been discussed. The identified association of markers and tolerance should be useful to pyramid favorable alleles for BYD tolerance into individual oat lines.     

Intergeneric protoplast fusion between Kluyveromyces and Saccharomyces cerevisiae – to produce sorbitol from Jerusalem artichokes

The construction of inulin-assimilating and sorbitol-producing fusants was achieved by intergeneric protoplast fusion between Kluyveromyces sp. Y-85 and Saccharomyces cerevisiae E-15. The cells of parental strains were pretreated with 0.1% EDTA (w/v) and 2-mercaptoethanol (0.1%, v/v) and then exposed to 2.0% (w/v) Zymolase at 30 °C for 30–40 min. The optimized fusion condition demonstrated that with the presence of 30% (w/v) polyethylene glycol 6000 (PEG-6000) and 10 mM CaCl₂ for 30 min, the fusion frequency reached 2.64 fusants/10⁶ parental cells. The fusants were screened by different characters between two parental strains and further identified by DNA contents, inulinase activity and sorbitol productivity. One of the genetically stable fusants, Strain F27, reached a maximal sorbitol production of 4.87 g/100 ml under optimal fermentation condition.     

Purification, characterization, and cDNA cloning of a new fibrinogenlytic venom protein, Agkisacutacin, from Agkistrodon acutus venom

Agkisacutacin is a new fibrinogenlytic protein from Agkistrodon acutus venom. It consists of two heterologous subunits linked by an intersubunit disulfide bond. The cDNAs encoding the two chains of Agkisacutacin were cloned from a lambdagt11 cDNA library of the snake venom gland and sequenced, including the leader peptides (23/23 amino acid residues) and mature subunits (129/123 amino acid residues). It is structurally related to the family of IX/X-binding protein (IX/X-bp)-like proteins and shows high similarity (alpha-70%/beta-64%) to habu IX/X-bp from Trimeresurus flavoridis, but displays distinct biological activity with direct action on fibrinogen.     

RNA-seq analysis reveals a key role of brassinolide-regulated pathways in NaCl-stressed cotton

Brassinolide (BL) alleviates salt injury in cotton seedlings; however, little is known about the molecular mechanisms of this response. In this study, digital gene expression analysis was performed to better understand the regulatory pathways of BL in NaCl-stressed cotton (Gossypium hirsutum L.). Compared with control plants (CK), a total of 1 162 and 7 659 differentially expressed genes (DEGs) were detected in the leaves and roots of NaCl-treated plants, respectively. Most of the DEGs in NaCl-treated plants, compared to CK, were regulated by BL. Moreover, expression patterns of DEGs in BL+NaCl treated plants were similar to those in CK plants; however, the responses of DEGs in the leaves and roots of NaCl-treated plants to BL differed. In the roots, BL-regulated DEGs were involved in protein biosynthesis, whereas in the leaves, BL promoted photosynthesis in NaCl-stressed cotton. BL treatment also significantly increased the overall biomass, chlorophyll a + b content in leaves, and the protein content in roots in NaCl-stressed cotton. The downregulation of stress-responsive genes in BL+NaCl-stressed leaves was also found. These results suggest that BL can alleviate NaCl injury in cotton plants.     

Intentionally introduced species: more easily invited than removed

Alien species are brought into countries world wide on a massive scale for agricultural production, ex situ conservation, landscape aesthetics, gardens, and ecosystem restoration. Unfortunately, some of these species have escaped and adversely impacted on regional as well as global biodiversity conservation and agricultural production. To reduce such risks, it is necessary to implement specific and effective measures. Since various government departments and institutions are involved in the management of alien species, it is difficult to prevent native and agroecosystems from being invaded by invited species. We propose the establishment of a supervision and inspection continuum over intentional species introduction, similar to that which exists in some countries over unintentional species introductions. Namely, a justification of the necessity to import, a risk assessment, assurances as to provision of an adequate containment facility assessment, and a damage-limitation protocol should that need to be invoked. These requirements should be satisfied before an alien species is knowingly imported, and the necessary follow-up supervision is important post- importation.