| 1. |
- Waszczak, Cezary, et al.
(författare)
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Synthesis and import of GDP-l-fucose into the Golgi affect plant–water relations
- 2023
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Ingår i: New Phytologist. - 0028-646X .- 1469-8137. ; 241:2, s. 747-63
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Tidskriftsartikel (refereegranskat)abstract
- Land plants evolved multiple adaptations to restrict transpiration. However, the underlying molecular mechanisms are not sufficiently understood. We used an ozone-sensitivity forward genetics approach to identify Arabidopsis thaliana mutants impaired in gas exchange regulation. High water loss from detached leaves and impaired decrease of leaf conductance in response to multiple stomata-closing stimuli were identified in a mutant of MURUS1 (MUR1), an enzyme required for GDP-l-fucose biosynthesis. High water loss observed in mur1 was independent from stomatal movements and instead could be linked to metabolic defects. Plants defective in import of GDP-l-Fuc into the Golgi apparatus phenocopied the high water loss of mur1 mutants, linking this phenotype to Golgi-localized fucosylation events. However, impaired fucosylation of xyloglucan, N-linked glycans, and arabinogalactan proteins did not explain the aberrant water loss of mur1 mutants. Partial reversion of mur1 water loss phenotype by borate supplementation and high water loss observed in boron uptake mutants link mur1 gas exchange phenotypes to pleiotropic consequences of l-fucose and boron deficiency, which in turn affect mechanical and morphological properties of stomatal complexes and whole-plant physiology. Our work emphasizes the impact of fucose metabolism and boron uptake on plant–water relations.
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| 2. |
- Rai, Neha, et al.
(författare)
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How do cryptochromes and UVR8 interact in natural and simulated sunlight?
- 2019
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Ingår i: Journal of Experimental Botany. - : Oxford University Press. - 0022-0957 .- 1460-2431. ; 70:18, s. 4975-4990
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Tidskriftsartikel (refereegranskat)abstract
- Cryptochromes (CRYs) and UV RESISTANCE LOCUS 8 (UVR8) photoreceptors perceive UV-A/blue (315–500 nm) and UV-B (280–315 nm) radiation in plants, respectively. While the roles of CRYs and UVR8 have been studied in separate controlled environment experiments, little is known about the interaction between these photoreceptors. Here, Arabidopsis thaliana wild-type Ler, CRYs and UVR8 photoreceptor mutants (uvr82, cry1cry2 and cry1cry2uvr82), and a flavonoid biosynthesis defective mutant (tt4) were grown in a sun simulator. Plants were exposed to filtered radiation for 17 d or for 6 h, to study the effects of blue, UV-A and UV-B radiation. Both CRYs and UVR8 independently enabled growth and survival of plants under solar levels of UV, while their joint absence was lethal under UV-B. CRYs mediated gene expression under blue light. UVR8 mediated gene expression under UV-B radiation, and in the absence of CRYs, also under UV-A. This negative regulation of UVR8-mediated gene expression by CRYs was also observed for UV-B. The accumulation of flavonoids was also consistent with this interaction between CRYs and UVR8. In conclusion, we provide evidence for an antagonistic interaction between CRYs and UVR8 and a role of UVR8 in UV-A perception.
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