Developing smart crops which yield more biomass to meet the increasing demand for plant biomass has been an active area of research in last few decades. We investigated metabolic alterations in two... Show moreDeveloping smart crops which yield more biomass to meet the increasing demand for plant biomass has been an active area of research in last few decades. We investigated metabolic alterations in two Arabidopsis thaliana mutants with enhanced growth characteristics that were previously obtained from a collection of plant lines expressing artificial transcription factors. The metabolic profiles were obtained directly from intact Arabidopsis leaves using high-resolution magic angle spinning (HR-MAS) NMR. Multivariate analysis showed significant alteration of metabolite levels between the mutants and the wild-type Col-0. Interestingly, most of the metabolites that were reduced in the faster-growing mutants are generally involved in the defence against stress. These results suggest a growth-defence trade-off in the phenotypically engineered mutants. Our results further corroborate the idea that plant growth can be enhanced by suppressing defence pathways. Show less
Tol, N. van; Flores Andaluz, G.; Leeggangers, H.A.C.F.; Roushan, M.R.; Hooykaas, P.J.J.; Zaal, E.J. van der 2018
The large majority of core photosynthesis proteins in plants are encoded by nuclear genes, but a small portion have been retained in the plastid genome. These plastid-encoded chloroplast proteins... Show moreThe large majority of core photosynthesis proteins in plants are encoded by nuclear genes, but a small portion have been retained in the plastid genome. These plastid-encoded chloroplast proteins fulfill essential roles in the process of photochemistry. Here, we report the use of nuclear-encoded, chloroplast-targeted zinc finger artificial transcription factors (ZF-ATFs) with effector domains of prokaryotic origin to modulate the expression of chloroplast genes, and to enhance the photochemical activity and growth characteristics of Arabidopsis thaliana plants. This technique was named chloroplast genome interrogation. Using this novel approach, we obtained evidence that ZF-ATFs can indeed be translocated to chloroplasts of Arabidopsis plants, can modulate their growth and operating light use efficiency of PSII, and finally can induce statistically significant changes in the expression levels of several chloroplast genes. Our data suggest that the distortion of chloroplast gene expression might be a feasible approach to manipulate the efficiency of photosynthesis in plants. Show less
Tol, N. van; Rolloos, A.M.; Loon, P. van; Zaal, E.J. van der 2018
Agrobacterium mediated transformation (AMT) has been embraced by biotechnologists as the technology of choice to introduce or alter genetic traits of plants. However, in plants it is virtually... Show moreAgrobacterium mediated transformation (AMT) has been embraced by biotechnologists as the technology of choice to introduce or alter genetic traits of plants. However, in plants it is virtually impossible to predetermine the integration site of the transferred T-strand unless one is able to generate a double stranded break (DSB) in the DNA at the site of interest. In this study, we used the model organism Saccharomyces cerevisiae to investigate whether the Agrobacterium mediated translocation of site-specific endonucleases via the type IV secretion system (T4SS), concomitantly with T-DNA transfer is possible and whether this can improve the gene targeting efficiency. In addition to that, the effect of different chromatin states on targeted integration, was investigated. It was found that Agrobacterium mediated translocation of the homing endonuclease I-SceI has a positive effect on the integration of T-DNA via the homologous repair (HR) pathway. Furthermore, we obtained evidence that nucleosome removal has a positive effect on I-SceI facilitated T-DNA integration by HR. Reversely; inducing nucleosome formation at the site of integration removes the positive effect of translocated I-SceI on T-DNA integration. Show less
Qi, J.; Verk, M.C. van; Pinas, J.E.; Lindhout, B.I.; Hooykaas, P.J.J.; Zaal, E.J. van der 2013
