Cisgenesis and intragenesis as new strategies for crop improvement

Cisgenesis and intragenesis are emerging plant breeding technologies which offer great promise for future acceptance of genetically engineered crops. The techniques employ traditional genetic engineering methods but are confined to transferring of genes and genetic elements between sexually compatible species that can breed naturally. One of the main requirements is the absence of selectable marker genes (such as antibiotic resistance genes) in the genome. Hence the sensitive issues with regard to transfer of foreign genes and antibiotic resistance are overcome. It is a targeted technique involving specific locus; therefore, linkage drag that prolongs the time for crop improvement in traditional breeding does not occur. It has great potential for crop improvement using superior alleles that exist in the untapped germplasm or wild species. Cisgenic and intragenic plants may not face the same stringent regulatory assessment for field release as transgenic plants which is a clear added advantage that would save time. In this chapter, the concepts of cis/intragenesis and the prerequisites for the development of cis/intragenesis plants are elaborated. Strategies for marker gene removal after selection of transformants are discussed based on the few recent reports from various plant species

Is biotechnology (more) acceptable when it enables a reduction in phytosanitary treatments? A European comparison of the acceptability of transgenesis and cisgenesis

Reduced pesticide use is one of the reasons given by Europeans for accepting new genetic engineering techniques. According to the advocates of these techniques, consumers are likely to embrace the application of cisgenesis to apple trees. In order to verify the acceptability of these techniques, we estimate a Bayesian multilevel structural equation model, which takes into account the multidimensional nature of acceptability and individual, national, and European effects, using data from the Eurobarometer 2010 73.1 on science. The results underline the persistence of clear differences between European countries and whilst showing considerable defiance, a relatively wider acceptability of vertical gene transfer as a means of reducing phytosanitary treatments, compared to horizontal transfer

Direct determination of Zn in individual Daphnia magna specimens by means of solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry

In this work, the capabilities of solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry (GFAAS) for the direct determination of the Zn body burden in individual specimens of Daphnia magna (small aquatic invertebrates of approx. 2 mm length that are widely used in ecotoxicological research) were investigated. It was concluded that this technique offers interesting features for this type of application, permitting the fast (approx. 2 min for the measurement of a single sample) and practically contamination-free analysis of these invertebrates, as the only preparation required is drying. Moreover, one of the traditional disadvantages of line source-GFAAS, the narrow linear range achieved using a particular set of experimental conditions, can be overcome with this technique by the judicious selection of the detector pixels used for signal quantification, such that the linear range can be extended simply by reprocessing the data, without the need to carry out any additional measurement. This feature is particularly interesting for this application, since every Daphnia magna specimen can be monitored only once, and thus, there is no possibility to alter the conditions and repeat the analysis for samples displaying a Zn content outside the linear range. In this case, the use of central and/or side pixels permits achieving a working range between 5 and 400 ng for the 307.590 nm Zn line, which is fit-for-purpose. Analysis of two biological certified reference materials (SRM 1549 Non-fat milk powder and SRM 1577b Bovine liver) was also investigated, and accuracy could be demonstrated when carrying out the calibration versus aqueous standard solutions

Isolation and functional characterisation of banana phytoene synthase genes as potential cisgenes

Carotenoids occur in all photosynthetic organisms where they protect photosystems from auto-oxidation, participate in photosynthetic energy-transfer and are secondary metabolites. Of the more than 600 known plant carotenoids, few can be converted into vitamin A by humans and so these pro-vitamin A carotenoids (pVAC) are important in human nutrition. Phytoene synthase (PSY) is a key enzyme in the biosynthetic pathway of pVACs and plays a central role in regulating pVAC accumulation in the edible portion of crop plants. Bananas are a major commercial crop and serve as a staple crop for more than 30 million people. There is natural variation in fruit pVAC content across different banana cultivars, but this is not well understood. Therefore, we isolated PSY genes from banana cultivars with relatively high (cv. Asupina) and low (cv. Cavendish) pVAC content. We provide evidence that PSY in banana is encoded by two paralogs (PSY1 and PSY2), each with a similar gene structure to homologous genes in other monocots. Further, we demonstrate that PSY2 is more highly expressed in fruit pulp compared to leaf. Functional analysis of PSY1 and PSY2 in rice callus and E. coli demonstrate that both genes encode functional enzymes, and that Asupina PSYs have approximately twice the enzymatic activity of the corresponding Cavendish PSYs. These results suggest that differences in PSY enzyme activity contribute significantly to the differences in Asupina and Cavendish fruit pVAC content. Importantly, Asupina PSY genes could potentially be used to generate new cisgenic or intragenic banana cultivars with enhanced pVAC content

Shaping professional development of educators: The role of school leaders

This chapter focuses on the influence of principal leadership on practising teachers’ continuous professional learning. It adopts a qualitative methodology and reviews the findings and recommendations of recently published peer-reviewed journal articles and the occasional international policy report, which explicitly refer to principal leadership and its role in teacher professional learning to enhance student learning. The results of this systematic review suggest that leadership is a crucial element in impactful teacher professional learning. The chapter provides a list of strategies that school leaders can employ to increase the likelihood of more effective teacher professional learning in their schools. Some considerations for principals include adopting a blend of transformational and instructional leadership approaches; building trust and credibility; making the learning of teachers, as well as students, their focused priority and providing a range of support mechanisms to ensure that allocated professional learning delivers improvements in teaching quality and practices that will result in increased student learning outcomes. This chapter adds to the research knowledge that suggests that leadership has an indirect impact on student learning and that teachers’ continuous professional learning must become more effective if it is to deliver the necessary positive growth in student learning.Lynda MacLeo