The UV RESISTANCE LOCUS 8-Mediated UV-B Response Is Required Alongside CRYPTOCHROME1 For Plant Survival Under Sunlight In The Field

Abstract

As sessile organisms, plants are subjected to fluctuating sunlight including potentially detrimental ultraviolet-B radiation (UV-B). In Arabidopsis thaliana, experiments under controlled conditions have shown that UV RESISTANCE LOCUS 8 (UVR8) controls photomorphogenic responses for acclimation and tolerance to UV-B; however, its long-term impacts on plant performance remain poorly understood in naturally fluctuating environments. Here we quantified the survival and reproduction of different Arabidopsis mutant genotypes in diverse field and laboratory conditions. We found that uvr8 mutants produced more fruits than wild type in growth chambers with artificial low UV-B conditions but not in natural field conditions. Importantly, independent double mutants of UVR8 and the blue-light photoreceptor gene CRYPTOCHROME 1 (CRY1) in two genetic backgrounds showed a drastic reduction in fitness in the field. UV-B attenuation experiments in field conditions and supplemental UV-B in growth chambers demonstrated that UV-B caused the conditional cry1 uvr8 lethality phenotype. RNA sequencing in different conditions revealed a large number of genes with statistical interaction of UVR8 and CRY1 mutations in the presence of UV-B in the field. Among them, Gene Ontology analysis identified enrichment of categories related to UV-B response, oxidative stress, photoprotection and DNA damage repair. Our study demonstrates the functional importance of the UVR8-mediated response across life stages in natura, which is partially redundant with CRY1, and provides an integral picture of gene expression associated with plant environmental responses under diverse environmental conditions.

PlantServation: time-series phenotyping using machine learning revealed seasonal pigment fluctuation in diploid and polyploidArabidopsis

“…Field observations of A. thaliana and its relatives will enable the study of plant responses in the field, taking the advantage of a large number of studies in regulated chambers as well as mutant collections. For example, destructive sampling of A. thaliana showed that anthocyanin content was reduced in the double mutants of UVR8 and CRY1 photoreceptor genes in the field 62 , which can be extended to time-course studies. By connecting to solar power, PlantServation can be deployed at remote natural sites to observe diverse species.…”

Genome-wide association study of aphid abundance highlights a locus affecting plant growth and flowering inArabidopsis thaliana

“…Recent studies have shown that controlled laboratory conditions are unlikely to reflect outdoor environments where interspecific interactions typically occur [19,20]. This fact emphasizes the importance of in natura studies of functional genes [21][22][23][24][25]. To achieve this goal, it is important to conduct GWAS under field conditions.…”

“…Arabidopsis thaliana is a model plant species distributed and naturalized around the world. While A. thaliana usually blooms in spring after over-wintering, some cohorts have overlapping life cycles from spring to autumn [25][26][27]. When A. thaliana plants emerge from late spring to early summer, they are threatened by various herbivores [4,28].…”

Genome-wide association study highlights escape from aphids by delayed growth inArabidopsis thaliana

“…Recent studies showed that controlled laboratory conditions are unlikely to reflect outdoor environments where interspecific interactions typically occur [17,18]. This fact emphasizes the importance of in natura study of functional genes [19][20][21][22][23]. To achieve this goal, it is important to conduct GWAS under field conditions.…”

“…Arabidopsis thaliana is a model plant species distributed and naturalized around the world. While A. thaliana usually blooms in spring after over-wintering, some cohorts have overlapping life cycles from spring to autumn [23–25]. When A. thaliana plants emerge from late spring to early summer, they are threatened by various herbivores [4,26].…”