The Different Faces of Arabidopsis arenosa—A Plant Species for a Special Purpose

The following review article collects information on the plant species Arabidopsis arenosa. Thus far, A. arenosa has been known as a model species for autotetraploidy studies because, apart from diploid individuals, there are also tetraploid populations, which is a unique feature of this Arabidopsis species. In addition, A arenosa has often been reported in heavy metal-contaminated sites, where it occurs together with a closely related species A. halleri, a model plant hyperaccumulator of Cd and Zn. Recent studies have shown that several populations of A. arenosa also exhibit Cd and Zn hyperaccumulation. However, it is assumed that the mechanism of hyperaccumulation differs between these two Arabidopsis species. Nevertheless, this phenomenon is still not fully understood, and thorough research is needed. In this paper, we summarize the current state of knowledge regarding research on A. arenosa.

Are drought resistance strategies associated with life history strategy? A commentary on: ‘Arabidopsis species deploy distinct strategies to cope with drought stress’

This article comments on: M. Bouzid, F. He, G. Schmitz, R. E. Häusler, A. P. M. Weber, T. Mettler-Altmann and J. de Meaux. 2019. Arabidopsis species deploy distinct strategies to cope with drought stress. Annals of Botany 124(1): 27–40.

Protein lysine methylation is involved in modulating the response of sensitive and tolerant Arabidopsis species to cadmium stress

ABSTRACTThe mechanisms underlying the response and adaptation of plants to excess of trace elements are not fully described. Here, we analyzed the importance of protein lysine methylation for plants to cope with cadmium. We analyzed the effect of cadmium on lysine-methylated proteins and protein lysine methyltransferases (KMTs) in two cadmium-sensitive species, Arabidopsis thaliana and A. lyrata, and in three populations of A. halleri with contrasting cadmium accumulation and tolerance traits. We showed that some proteins are differentially methylated at lysine residues in response to Cd and that a few genes coding KMTs is regulated by cadmium. Also, we showed that nine out of 23 A. thaliana mutants interrupted in KMT genes have a tolerance to cadmium that is significantly different from that of wild-type seedlings. We further characterized two of these mutants, one was knocked-out in the calmodulin lysine methyltransferase gene and displayed increased tolerance to cadmium, the other was interrupted in a KMT gene of unknown function and showed a decreased capacity to cope with cadmium. Together, our results showed that lysine methylation of non-histone proteins is impacted by cadmium and that several methylation events are important for modulating the response of Arabidopsis plants to cadmium stress.

Arabidopsis species deploy distinct strategies to cope with drought stress

Background and Aims Water limitation is an important determinant of the distribution, abundance and diversity of plant species. Yet, little is known about how the response to limiting water supply changes among closely related plant species with distinct ecological preferences. Comparison of the model annual species Arabidopsis thaliana with its close perennial relatives A. lyrata and A. halleri, can help disentangle the molecular and physiological changes contributing to tolerance and avoidance mechanisms, because these species must maintain tolerance and avoidance mechanisms to increase long-term survival, but they are exposed to different levels of water stress and competition in their natural habitat. Methods A dry-down experiment was conducted to mimic a period of missing precipitation. The covariation of a progressive decrease in soil water content (SWC) with various physiological and morphological plant traits across a set of representative genotypes in A. thaliana, A. lyrata and A. halleri was quantified. Transcriptome changes to soil dry-down were further monitored. Key Results The analysis of trait covariation demonstrates that the three species differ in the strategies they deploy to respond to drought stress. Arabidopsis thaliana showed a drought avoidance reaction but failed to survive wilting. Arabidopsis lyrata efficiently combined avoidance and tolerance mechanisms. In contrast, A. halleri showed some degree of tolerance to wilting but it did not seem to protect itself from the stress imposed by drought. Transcriptome data collected just before plant wilting and after recovery corroborated the phenotypic analysis, with A. lyrata and A. halleri showing a stronger activation of recovery- and stress-related genes, respectively. Conclusions The response of the three Arabidopsis species to soil dry-down reveals that they have evolved distinct strategies to face drought stress. These strategic differences are in agreement with the distinct ecological priorities of the stress-tolerant A. lyrata, the competitive A. halleri and the ruderal A. thaliana.

An in silico comparative genomic report on transcription factors in three Arabidopsis species

Transcription factors (TF) are the elements, which regulate gene expression. Regulatory function of TFs play an important role in plant biological processes and mechanisms. They may interconnect with other transcription factors or functional genes to modulate their expression in response to an internal/external factor like life cycle stage, growth, development and stress. Arabidopsis is the well-known and the most used model organism. Transcription factors of three Arabidopsis species including A. halleri, A. lyrata and A. thaliana, were compared. basic/helix-loop-helix (bHLH) with 220 TFs was the most abundant family among three Arabidopsis species while MYB and MYB related families considering as a whole group were more than bHLH with 308 TFs. No STERILE APETALA (SAP) TF homolog was found for A.halleri. The common transcription factors among three species were 4,172 grouped in 1,212 clusters. The species-specific clustered TFs were 12, 30 and 58 for A. halleri, A. lyrata and A. thaliana respectively. Eight hundred ninety two single-copy gene clusters those have one gene copy from each species, i.e. 2,676 genes, were listed. Four hundred forty five TF singletons were not clustered and are unique among three species. For clustered TF belonging to each species, GO terms and SwissProt hits showed that A. halleri has two species-specific TFs involved in heavy metal response including Zinc finger protein AZF2 and two-component response regulator ARR11 while for A. lyrata specific TFs are involved in stress response and plant development. A. thaliana specific clustered TFs work on plant flower development and acclimation.

An in silico comparative genomic report on transcription factors in three Arabidopsis species

Transcription factors (TF) are the elements, which regulate gene expression. Regulatory function of TFs play an important role in plant biological processes and mechanisms. They may interconnect with other transcription factors or functional genes to modulate their expression in response to an internal/external factor like life cycle stage, growth, development and stress. Arabidopsis is the well-known and the most used model organism. Transcription factors of three Arabidopsis species including A. halleri, A. lyrata and A. thaliana, were compared. basic/helix-loop-helix (bHLH) with 220 TFs was the most abundant family among three Arabidopsis species while MYB and MYB related families considering as a whole group were more than bHLH with 308 TFs. No STERILE APETALA (SAP) TF homolog was found for A.halleri. The common transcription factors among three species were 4,172 grouped in 1,212 clusters. The species-specific clustered TFs were 12, 30 and 58 for A. halleri, A. lyrata and A. thaliana respectively. Eight hundred ninety two single-copy gene clusters those have one gene copy from each species, i.e. 2,676 genes, were listed. Four hundred forty five TF singletons were not clustered and are unique among three species. For clustered TF belonging to each species, GO terms and SwissProt hits showed that A. halleri has two species-specific TFs involved in heavy metal response including Zinc finger protein AZF2 and two-component response regulator ARR11 while for A. lyrata specific TFs are involved in stress response and plant development. A. thaliana specific clustered TFs work on plant flower development and acclimation.