An illustrated gardener's guide to transgenic Arabidopsis field experiments

Abstract

Summary• Field studies with transgenic Arabidopsis lines have been performed over 8 yr, to better understand the influence that certain genes have on plant performance. Many (if not most) plant phenotypes cannot be observed under the near constant, low-stress conditions in growth chambers, making field experiments necessary. However, there are challenges in performing such experiments: permission must be obtained and regulations obeyed, the profound influence of uncontrollable biotic and abiotic factors has to be considered, and experimental design has to be strictly controlled.• The aim here is to provide inspiration and guidelines for researchers who are not used to setting up such experiments, allowing others to learn from our mistakes.• This is believed to be the first example of a 'manual' for field experiments with transgenic Arabidopsis plants. Many of the challenges encountered are common for all field experiments, and many researchers from ecological backgrounds are skilled in such methods.• There is huge potential in combining the detailed mechanistic understanding of molecular biologists with ecologists' expertise in examining plant performance under field conditions, and it is suggested that more interdisciplinary collaborations will open up new scientific avenues to aid analyses of the roles of genetic and physiological variation in natural systems.

The Photosystem II Light-Harvesting Protein Lhcb3 Affects the Macrostructure of Photosystem II and the Rate of State Transitions in Arabidopsis

“…Even stn7 plants that lack the LHCII kinase and therefore do not perform state transitions at all under similar conditions show only a limited fitness reduction (Frenkel et al, 2008). Clearly, the experimental garden experiment does not pose a sufficient challenge to Arabidopsis plants with respect to state transitions.…”

“…The reproductive fitness of the plants was determined by estimating seed production as described by Kulheim et al (2002) and Frenkel et al (2008) The plants were grown in an experimental garden in randomized block design as described previously (Frenkel et al, 2008). At maturity, seed production was estimated by counting the number of siliques on all plants and estimating the number of seeds per siliques by counting five siliques per plant.…”

“…At maturity, seed production was estimated by counting the number of siliques on all plants and estimating the number of seeds per siliques by counting five siliques per plant. The average number of seeds per plant was then estimated (Frenkel et al, 2008).…”

“…A randomized block design was used as described previously (Kulheim et al, 2002;Frenkel et al, 2008), and the growth rate and seed set were quantified and compared with wild-type plants. No altered growth phenotype was observed for the koLhcb3 plants under field conditions, and the seed set was identical to that found for the wild-type plants (see Supplemental Table 3 online).…”

PROTON GRADIENT REGULATION5 Is Essential for Proper Acclimation of Arabidopsis Photosystem I to Naturally and Artificially Fluctuating Light Conditions

“…Confocal microscopy images from the mesophyll tissues of 9-d-old seedlings revealed smaller cells in pgr5 grown under fluctuating light compared with the wild type, likely explaining the retarded growth (see Supplemental Figure 1 online). No difference in the size of the pgr5 and wild-type cells Field experiment Natural outdoor conditions in Northern Sweden, with light intensity fluctuating irregularly due to clouds and shading by nearby vegetation (Külheim et al, 2002;Frenkel et al, 2008) 6-week-old mature leaves (4 weeks outside) 1 was observed in seedlings grown under constant light. After 18 d growth under fluctuating light, the pgr5 mutant still remained at the two-or four-leaf state, whereas the wild-type seedlings continued growing ( Figure 1B).…”