BACKGROUND: Brassicaceae is a family of green plants of high scientific and economic interest, including thale cress (Arabidopsis thaliana), cruciferous vegetables (cabbages) and rapeseed. RESULTS: We reconstruct an evolutionary framework of Brassicaceae composed of high-resolution ancestral karyotypes using the genomes of modern A. thaliana, Arabidopsis lyrata, Capsella rubella, Brassica rapa and Thellungiella parvula. The ancestral Brassicaceae karyotype (Brassicaceae lineages I and II) is composed of eight protochromosomes and 20,037 ordered and oriented protogenes. After speciation, it evolved into the ancestral Camelineae karyotype (eight protochromosomes and 22,085 ordered protogenes) and the proto-Calepineae karyotype (seven protochromosomes and 21,035 ordered protogenes) genomes. CONCLUSIONS: The three inferred ancestral karyotype genomes are shown here to be powerful tools to unravel the reticulated evolutionary history of extant Brassicaceae genomes regarding the fate of ancestral genes and genomic compartments, particularly centromeres and evolutionary breakpoints. This new resource should accelerate research in comparative genomics and translational research by facilitating the transfer of genomic information from model systems to species of agronomic interest.

AIMS: Brassicaceae cover crops can be used to suppress soil-borne pathogens. The aim was to investigate the effect of different brassicas with different glucosinolate profiles on the development of Aphanomyces pea root rot in subsequent pea plants, and the genetic potential of free-living N₂-fixing bacteria and ammonia oxidising bacteria (AOB) and archaea (AOA) performing key soil ecosystem services. METHODS: The Brassicaceae species Brassica juncea and Sinapis alba and non-Brassicaceae species Secale cereale were grown for 11-weeks in Aphanomyces euteiches infested soil at low and high nitrogen (N) fertiliser doses. After removing both shoots and roots of the cover crops, peas were grown as a bioassay to evaluate Aphanomyces pea root rot development. Soil was sampled before harvesting the cover crops and at the end of the bioassay. Volatile compounds were collected in the root-soil environment before harvesting the Brassicaceae cover crops to determine the concentration of isothiocyanates. The abundance of genes involved in N₂-fixing bacteria and ammonia oxidation in AOA and AOB were assessed. RESULTS: Pea root rot disease severity was reduced in Brassicaceae grown soil at the high N fertiliser dose. This was associated with increased growth of the cover crops. The growth of Brassicaceae did not suppress the abundance of N-cycling microbial communities, but rather increased the AOB at the end of the bioassay, most likely due to increased N availability. The disease suppressive effect was higher with S. alba than with B. juncea, and this coincided with a more diverse composition and higher concentration of aliphatic ITCs released from S. alba roots. Fewer nodules were formed after the Brassicaceae crops, especially Sinapis alba. CONCLUSIONS: Brassicaceae cover crops, particularly S. alba, can be used to control soil-borne pathogens without major side effects on the genetic potential of beneficial soil microorganisms involved in N cycling. However, less nodule formation after brassicas indicates an effect on rhizobium activity.

Brassicaceae is a family of green plants of high scientific and economic interest, including thale cress (Arabidopsis thaliana), cruciferous vegetables (cabbages) and rapeseed.We reconstruct an evolutionary framework of Brassicaceae composed of high-resolution ancestral karyotypes using the genomes of modern A. thaliana, Arabidopsis lyrata, Capsella rubella, Brassica rapa and Thellungiella parvula. The ancestral Brassicaceae karyotype (Brassicaceae lineages I and II) is composed of eight protochromosomes and 20,037 ordered and oriented protogenes. After speciation, it evolved into the ancestral Camelineae karyotype (eight protochromosomes and 22,085 ordered protogenes) and the proto-Calepineae karyotype (seven protochromosomes and 21,035 ordered protogenes) genomes.The three inferred ancestral karyotype genomes are shown here to be powerful tools to unravel the reticulated evolutionary history of extant Brassicaceae genomes regarding the fate of ancestral genes and genomic compartments, particularly centromeres and evolutionary breakpoints. This new resource should accelerate research in comparative genomics and translational research by facilitating the transfer of genomic information from model systems to species of agronomic interest.

In France, oilseed rape is getting highly infected since 1990 by the branched broomrape Phelipanche ramosa (L.) Pomel. Branched broomrape infection causes serious yield losses ranging from 5 to 100 %, notably in the Mediterranean area. P. ramosa is parasiting the plant roots. The growth of P. ramosa on Brassicaceae weeds has not been studied quantitatively so far, except for the model species Arabidopsis thaliana. Since P. ramosa has a fast development rate on the fast-growing A. thaliana, P. ramosa development should be slower on other slower-growing Brassicaceae species. Here, we cultivated in the laboratory seven Brassicaceae weed species including Capsella bursa-pastoris, Capsella rubella, Cardamine hirsuta, Lepidium campestre, Lepidium draba, Sinapis arvensis and A. thaliana as control, during 3 weeks. We counted the number of P. ramosa individuals that have reached the following growth stages: germination, attachment, tubercle, bud and underground stem. We then assessed the development rate of P. ramosa by calculating the odds ratio of attachment or higher development stages of P. ramosa on Brassicaceae, with A. thaliana as the reference. We found that five Brassicaceae species had an odds ratio ranging from 0.9 to 2.4. These ratios are thus similar or higher than that of the A. thaliana reference. This finding shows for the first time that P. ramosa develops faster on the five Brassicaceae species. This finding is also unexpected because A. thaliana is a fast-growing plant, whereas the five Brassicaceae species have a longer life cycle. Therefore, this observation demonstrates for the first time that P. ramosa development depends on others factors than the speed of plant host development.

In France, oilseed rape is getting highly infected since 1990 by the branched broomrape Phelipanche ramosa (L.) Pomel. Branched broomrape infection causes serious yield losses ranging from 5 to 100 %, notably in the Mediterranean area. P. ramosa is parasiting the plant roots. The growth of P. ramosa on Brassicaceae weeds has not been studied quantitatively so far, except for the model species Arabidopsis thaliana. Since P. ramosa has a fast development rate on the fast-growing A. thaliana, P. ramosa development should be slower on other slower-growing Brassicaceae species. Here, we cultivated in the laboratory seven Brassicaceae weed species including Capsella bursa-pastoris, Capsella rubella, Cardamine hirsuta, Lepidium campestre, Lepidium draba, Sinapis arvensis and A. thaliana as control, during 3 weeks. We counted the number of P. ramosa individuals that have reached the following growth stages: germination, attachment, tubercle, bud and underground stem. We then assessed the development rate of P. ramosa by calculating the odds ratio of attachment or higher development stages of P. ramosa on Brassicaceae, with A. thaliana as the reference. We found that five Brassicaceae species had an odds ratio ranging from 0.9 to 2.4. These ratios are thus similar or higher than that of the A. thaliana reference. This finding shows for the first time that P. ramosa develops faster on the five Brassicaceae species. This finding is also unexpected because A. thaliana is a fast-growing plant, whereas the five Brassicaceae species have a longer life cycle. Therefore, this observation demonstrates for the first time that P. ramosa development depends on others factors than the speed of plant host development.

In France, oilseed rape is getting highly infected since 1990 by the branched broomrape Phelipanche ramosa (L.) Pomel. Branched broomrape infection causes serious yield losses ranging from 5 to 100 %, notably in the Mediterranean area. P. ramosa is parasiting the plant roots. The growth of P. ramosa on Brassicaceae weeds has not been studied quantitatively so far, except for the model species Arabidopsis thaliana. Since P. ramosa has a fast development rate on the fast-growing A. thaliana, P. ramosa development should be slower on other slower-growing Brassicaceae species. Here, we cultivated in the laboratory seven Brassicaceae weed species including Capsella bursa-pastoris, Capsella rubella, Cardamine hirsuta, Lepidium campestre, Lepidium draba, Sinapis arvensis and A. thaliana as control, during 3 weeks. We counted the number of P. ramosa individuals that have reached the following growth stages: germination, attachment, tubercle, bud and underground stem. We then assessed the development rate of P. ramosa by calculating the odds ratio of attachment or higher development stages of P. ramosa on Brassicaceae, with A. thaliana as the reference. We found that five Brassicaceae species had an odds ratio ranging from 0.9 to 2.4. These ratios are thus similar or higher than that of the A. thaliana reference. This finding shows for the first time that P. ramosa develops faster on the five Brassicaceae species. This finding is also unexpected because A. thaliana is a fast-growing plant, whereas the five Brassicaceae species have a longer life cycle. Therefore, this observation demonstrates for the first time that P. ramosa development depends on others factors than the speed of plant host development.

International audience | In France, oilseed rape is getting highly infected since 1990 by the branched broomrape Phelipanche ramosa (L.) Pomel. Branched broomrape infection causes serious yield losses ranging from 5 to 100 %, notably in the Mediterranean area. P. ramosa is parasiting the plant roots. The growth of P. ramosa on Brassicaceae weeds has not been studied quantitatively so far, except for the model species Arabidopsis thaliana. Since P. ramosa has a fast development rate on the fast-growing A. thaliana, P. ramosa development should be slower on other slower-growing Brassicaceae species. Here, we cultivated in the laboratory seven Brassicaceae weed species including Capsella bursa-pastoris, Capsella rubella, Cardamine hirsuta, Lepidium campestre, Lepidium draba, Sinapis arvensis and A. thaliana as control, during 3 weeks. We counted the number of P. ramosa individuals that have reached the following growth stages: germination, attachment, tubercle, bud and underground stem. We then assessed the development rate of P. ramosa by calculating the odds ratio of attachment or higher development stages of P. ramosa on Brassicaceae, with A. thaliana as the reference. We found that five Brassicaceae species had an odds ratio ranging from 0.9 to 2.4. These ratios are thus similar or higher than that of the A. thaliana reference. This finding shows for the first time that P. ramosa develops faster on the five Brassicaceae species. This finding is also unexpected because A. thaliana is a fast-growing plant, whereas the five Brassicaceae species have a longer life cycle. Therefore, this observation demonstrates for the first time that P. ramosa development depends on others factors than the speed of plant host development.

Verticillium longisporum is an economically important vascular pathogen of Brassicaceae crops in different parts of the world. V. longisporum is a diploid hybrid that consists of three different lineages, each of which originated from a separate hybridization event between two different sets of parental species. We used 20 isolates representing the three V. longisporum lineages and the relative V. dahliae, and performed pathogenicity tests on 11 different hosts, including artichoke, cabbage, cauliflower, cotton, eggplant, horseradish, lettuce, linseed, oilseed rape (canola), tomato, and watermelon. V. longisporum was overall more virulent on the Brassicaceae crops than V. dahliae, which was more virulent than V. longisporum across the non-Brassicaceae crops. There were differences in virulence between the three V. longisporum lineages. V. longisporum lineage A1/D1 was the most virulent lineage on oilseed rape, and V. longisporum lineage A1/D2 was the most virulent lineage on cabbage and horseradish. We also found that on the non-Brassicaceae hosts eggplant, tomato, lettuce, and watermelon, V. longisporum was more or equally virulent than V. dahliae. This suggests that V. longisporum may have a wider potential host range than currently appreciated.

International audience | Camelina sativa is a Brassicaceae that was commonly cultivated in Europe until the 19th century. Recently, it has received much interest as an alternative oil-seed crop because of its particular oil composition and low requirements in terms of agronomic inputs and its resistance to some Brassicaceae chewing insects. However, little is known about the consequences of its reintroduction on piercing-sucking insects pests that are not Brassicaceae specialists but that are likely to transmit phytoviruses. In this context, laboratory experiments were conducted to investigate the potential colonization of camelina by four major aphid species of northern France. Orientation tests, feeding behavior assessed by Electrical Penetration Graph and demographic bioassays showed that the polyphagous species, Aphis fabae (Scop) and Myzus persicae (Sulzer), were able to land, feed, and reproduce on the plant. They even fed and performed better on camelina than the Brassicaceae specialist Brevicoryne brassicae (L.). Surprisingly, to a lesser extent, Camelina sativa could also be a suitable host for the cereal specialist Rhopalosiphum padi (L.). The colonization ability of camelina by the different aphids is discussed in terms of the degree of specialization and physico-chemical characteristics of the plant. Camelina may therefore constitute a reservoir for aphid species issued from surrounding crops and their associated.

International audience | Camelina sativa is a Brassicaceae that was commonly cultivated in Europe until the 19th century. Recently, it has received much interest as an alternative oil-seed crop because of its particular oil composition and low requirements in terms of agronomic inputs and its resistance to some Brassicaceae chewing insects. However, little is known about the consequences of its reintroduction on piercing-sucking insects pests that are not Brassicaceae specialists but that are likely to transmit phytoviruses. In this context, laboratory experiments were conducted to investigate the potential colonization of camelina by four major aphid species of northern France. Orientation tests, feeding behavior assessed by Electrical Penetration Graph and demographic bioassays showed that the polyphagous species, Aphis fabae (Scop) and Myzus persicae (Sulzer), were able to land, feed, and reproduce on the plant. They even fed and performed better on camelina than the Brassicaceae specialist Brevicoryne brassicae (L.). Surprisingly, to a lesser extent, Camelina sativa could also be a suitable host for the cereal specialist Rhopalosiphum padi (L.). The colonization ability of camelina by the different aphids is discussed in terms of the degree of specialization and physico-chemical characteristics of the plant. Camelina may therefore constitute a reservoir for aphid species issued from surrounding crops and their associated.