The effect of endogenous mRNA levels on co-suppression in tomato

AbstractIntroduction of truncated polygalacturonase (PG) transgenes into tomato plants caused the production of small interfering RNAs (siRNAs) and co-suppression of both the endogenous and PG transgenes in ripening fruits by post-transcriptional gene silencing. In order to test the possible effect on co-suppression of the endogenous PG mRNA level, we transferred the PG transgenes from a PG-silenced line (wild type background) by crossing to two ripening regulatory mutants with reduced PG: Never-ripe (Nr, ∼10% endogenous PG mRNA compared to wild type) and ripening-inhibitor (rin, ∼1% endogenous PG mRNA) and to wild type (as a control). The PG transgenes caused strong co-suppression of the transgenes and the endogenous PG gene in cells with high PG mRNA background (wild type) and silencing appeared to be linked with higher transgene copy number and/or a particular transgene locus. In cells with low endogenous PG mRNA accumulation (Nr), the endogenous PG gene was preferentially suppressed compared to the transgenes, whose expression was not reduced significantly. The expression of the transgenes was also not reduced in the very low PG background (rin), in which endogenous PG was barely detectable. In all the analysed lines with all three PG background levels, siRNAs accumulated in leaves and green fruits, in which the endogenous PG gene is not transcribed. The relatively abundant production of siRNAs in most of the lines was linked with a particular transgene insert. These results suggest that a certain threshold level of endogenous PG mRNA is required for the co-suppression of the truncated PG transgenes and the endogenous PG gene or for extensive silencing of the transgenes

Examine Primary School Teachers' Attitudes Towards Technology Integration in Primary Education

In today's society, information and communication technology (ICT) has become an ever-present force, deeply ingrained in all aspects of our lives. Its crucial role in our daily routines highlights its significance, especially in education. This paper focuses on exploring the viewpoints of primary school teachers regarding integrating technology in their classrooms. Additionally, it examines how educators' academic backgrounds and years of teaching experience may influence their attitudes toward technology in primary education. A quantitative survey with a convenient sampling of 50 teachers was employed in this study. The research objectives include identifying primary teachers' attitudes toward technology use and investigating potential differences based on teaching experience and educational qualifications. The results highlight an increasing necessity to explore the subtle motivations and concerns that underpin teachers' technological attitudes

Joint Communication and Computation Design in Transmissive RMS Transceiver Enabled Multi-Tier Computing Networks

In this paper, a novel transmissive reconfigurable meta-surface (RMS) transceiver enabled multi-tier computing network architecture is proposed for improving computing capability, decreasing computing delay and reducing base station (BS) deployment cost, in which transmissive RMS equipped with a feed antenna can be regarded as a new type of multi-antenna system. We formulate a total energy consumption minimization problem by a joint optimization of subcarrier allocation, task input bits, time slot allocation, transmit power allocation and RMS transmissive coefficient while taking into account the constraints of communication resources and computing resources. This formulated problem is a non-convex optimization problem due to the high coupling of optimization variables, which is NP-hard to obtain its optimal solution. To address the above challenging problems, block coordinate descent (BCD) technique is employed to decouple the optimization variables to solve the problem. Specifically, the joint optimization problem of subcarrier allocation, task input bits, time slot allocation, transmit power allocation and RMS transmissive coefficient is divided into three subproblems to solve by applying BCD. Then, the decoupled three subproblems are optimized alternately by using successive convex approximation (SCA) and difference-convex (DC) programming until the convergence is achieved. Numerical results verify that our proposed algorithm is superior in reducing total energy consumption compared to other benchmarks