Floral attraction traits can significantly affect pollinator visitation patterns, but adaptive evolution of these traits may be constrained by correlations with other traits. In some cases, molecular pathways contributing to floral attraction are well characterized, offering the opportunity to explore loci potentially underlying variation among individuals. Here, we quantify the range of variation in floral
Concentrations of ground‐level ozone ([O3]) over much of the Earth's land surface have more than doubled since pre‐industrial times. The air pollutant is highly variable over time and space, which makes it difficult to assess the average agronomic and economic impacts of the pollutant as well as to breed crops for O3tolerance. Recent modeling efforts have improved quantitative understanding of the effects of current and future [O3] on global crop productivity, and experimental advances have improved understanding of the cellular O3sensing, signaling and response mechanisms. This work provides the fundamental background and justification for breeding and biotechnological approaches for improving O3tolerance in crops. There is considerable within‐species variation in O3tolerance in crops, which has been used to create mapping populations for screening. Quantitative trait loci (
- NSF-PAR ID:
- 10037343
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- The Plant Journal
- Volume:
- 90
- Issue:
- 5
- ISSN:
- 0960-7412
- Page Range / eLocation ID:
- p. 886-897
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
Abstract UV patterning (i.e.UV ‘bulls‐eye nectar guides) among crop and wild accessions ofBrassica rapa . We then use experimental crosses to examine the genetic architecture, candidate loci and biochemical underpinnings of this patterning as well as phenotypic manipulations to test the ecological impact. We find qualitative variation inUV patterning between wild (commonly lackingUV patterns) and crop (commonly exhibitingUV patterns) accessions. Similar to the majority of crops, recombinant inbred lines (RIL s) derived from an oilseed crop ×WI fast‐plant®cross exhibitUV patterns, the size of which varies extensively among genotypes. InRIL s, we further observe strong statistical‐genetic andQTL correlations within petal morphological traits and within measurements of petalUV patterning; however, correlations between morphology andUV patterning are weak or nonsignificant, suggesting thatUV patterning is regulated and may evolve independently of overall petal size.HPLC analyses reveal a high concentration of sinapoyl glucose inUV ‐absorbing petal regions, which, in concert with physical locations ofUV ‐traitQTL s, suggest a regulatory and structural gene as candidates underlying observed quantitative variation. Finally, insects prefer flowers withUV bulls‐eye patterns over those that lack patterns, validating the importance ofUV patterning in pollen‐limited populations ofB. rapa . -
Convergent evolution of root system architecture in two independently evolved lineages of weedy rice
Summary Root system architecture (
RSA ) is a critical aspect of plant growth and competitive ability. Here we used two independently evolved strains of weedy rice, a de‐domesticated form of rice, to study the evolution of weed‐associatedRSA traits and the extent to which they evolve through shared or different genetic mechanisms.We characterised 98 two‐dimensional and three‐dimensional
RSA traits in 671 plants representing parents and descendants of two recombinant inbred line populations derived from two weed × crop crosses. A random forest machine learning model was used to assess the degree to which root traits can predict genotype and the most diagnostic traits for doing so. We used quantitative trait locus (QTL) mapping to compare genetic architecture between the weed strains.The two weeds were distinguishable from the crop in similar and predictable ways, suggesting independent evolution of a ‘weedy’
RSA phenotype. Notably, comparativeQTL mapping revealed little evidence for shared underlying genetic mechanisms.Our findings suggest that despite the double bottlenecks of domestication and de‐domestication, weedy rice nonetheless shows genetic flexibility in the repeated evolution of weedy
RSA traits. Whereas the root growth of cultivated rice may facilitate interactions among neighbouring plants, the weedy rice phenotype may minimise below‐ground contact as a competitive strategy. -
Abstract Microgeographic adaptation provides a particularly interesting context for understanding the genetic basis of phenotypic divergence and may also present unique empirical challenges. In particular, plant adaptation to extreme soil mosaics may generate barriers to gene flow or shifts in mating system that confound simple genomic scans for adaptive loci. Here, we combine three approaches – quantitative trait locus (QTL) mapping of candidate intervals in controlled crosses, population resequencing (PoolSeq) and analyses of wild recombinant individuals – to investigate one trait associated with
Mimulus guttatus (yellow monkeyflower) adaptation to geothermal soils in Yellowstone National Park. We mapped a majorQTL causing dense leaf trichomes in thermally adapted plants to a <50‐kb region of linkage Group 14 (Tr14) previously implicated in trichome divergence between independentM. guttatus populations. A PoolSeq scan of Tr14 region revealed a cluster of six genes, coincident with the inferredQTL peak, with high allele frequency differences sufficient to explain observed phenotypic differentiation. One of these, the R2R3MYB transcription factor Migut.N02661, is a plausible functional candidate and was also strongly associated (r 2 = 0.27) with trichome phenotype in analyses of wild‐collected admixed individuals. Although functional analyses will be necessary to definitively link molecular variants in Tr14 with trichome divergence, our analyses are a major step in that direction. They point to a simple, and parallel, genetic basis for one axis ofMimulus guttatus adaptation to an extreme habitat, suggest a broadly conserved genetic basis for trichome variation across flowering plants and pave the way for further investigations of this challenging case of microgeographic incipient speciation. -
Summary The altered carbon assimilation pathway of crassulacean acid metabolism (
CAM ) photosynthesis results in an up to 80% higher water‐use efficiency than C3photosynthesis in plants making it a potentially useful pathway for engineering crop plants with improved drought tolerance. Here we surveyed detailed temporal (diel time course) and spatial (across a leaf gradient) gene and microRNA (miRNA ) expression patterns in the obligateCAM plant pineapple [Ananas comosus (L.) Merr.]. The high‐resolution transcriptome atlas allowed us to distinguish betweenCAM ‐related and non‐CAM gene copies. A differential gene co‐expression network across green and white leaf diel datasets identified genes with circadian oscillation,CAM ‐related functions, and source‐sink relations. Gene co‐expression clusters containingCAM pathway genes are enriched with clock‐associatedcis ‐elements, suggesting circadian regulation ofCAM . About 20% of pineapple microRNA s have diel expression patterns, with several that target keyCAM ‐related genes. Expression and physiology data provide a model forCAM ‐specific carbohydrate flux and long‐distance hexose transport. Together these resources provide a list of candidate genes for targeted engineering ofCAM into C3photosynthesis crop species. -
Abstract Phenotypic plasticity allows organisms to change their phenotype in response to shifts in the environment. While a central topic in current discussions of evolutionary potential, a comprehensive understanding of the genetic underpinnings of plasticity is lacking in systems undergoing adaptive diversification. Here, we investigate the genetic basis of phenotypic plasticity in a textbook adaptive radiation, Lake Malawi cichlid fishes. Specifically, we crossed two divergent species to generate an F3hybrid mapping population. At early juvenile stages, hybrid families were split and reared in alternate foraging environments that mimicked benthic/scraping or limnetic/sucking modes of feeding. These alternate treatments produced a variation in morphology that was broadly similar to the major axis of divergence among Malawi cichlids, providing support for the flexible stem theory of adaptive radiation. Next, we found that the genetic architecture of several morphological traits was highly sensitive to the environment. In particular, of 22 significant quantitative trait loci (
QTL ), only one was shared between the environments. In addition, we identifiedQTL acting across environments with alternate alleles being differentially sensitive to the environment. Thus, our data suggest that while plasticity is largely determined by loci specific to a given environment, it may also be influenced by loci operating across environments. Finally, our mapping data provide evidence for the evolution of plasticity via genetic assimilation at an important regulatory locus,ptch1 . In all, our data address long‐standing discussions about the genetic basis and evolution of plasticity. They also underscore the importance of the environment in affecting developmental outcomes, genetic architectures, morphological diversity and evolutionary potential.