Heat-induced transposition leads to rapid drought resistance of Arabidopsis thaliana

Plant genomes comprise a vast diversity of transposable elements (TEs) (Tenaillon et al. 2010)⁠. While their uncontrolled proliferation can have fatal consequences for their host, there is strong evidence for their importance in fueling genetic diversity and plant evolution (Baduel et al. 2021)⁠. However, the number of studies addressing the role of TEs in this process is limited. Here we show that the heat-induced burst of a low-copy TE increases phenotypic diversity and leads to the rapid emergence of more drought-resistant individuals of Arabidopsis thaliana. We exposed TE-high-copy-(hc)lines (Thieme et al. 2017)⁠ with up to ~8 fold increased copy numbers of the heat-responsive ONSEN-TE (AtCOPIA78) (Ito et al. 2011; Cavrak et al. 2014; Tittel-Elmer et al. 2010)⁠ in the wild type background to desiccation as a straightforward and highly relevant selection pressure. We found evidence for a drastic increase of drought resistance in five out of the 23 tested hc-lines and further pinpoint one of the causative mutations to an exonic ONSEN-insertion in the ribose-5-phosphate-isomerase 2 gene. This loss-of-function mutation resulted in a decreased rate of photosynthesis and water consumption. This is one of the rare examples (Esnault et al. 2019)⁠ experimentally demonstrating the adaptive potential of mobilized stress-responsive TEs in eukaryotes. Our results further shed light on the complex relationship between mobile elements and their hosts and substantiate the importance of TE-mediated loss-of-function mutations in stress adaptation, particularly with respect to global warming.

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Phenotypic diversity created by a transposable element increases productivity and resistance to competitors in plant populations

10.1101/2021.10.04.462998 ◽

2021 ◽

Author(s):

Vít Latzel ◽

Javier Puy ◽

Michael Thieme ◽

Etienne Bucher ◽

Lars Götzenberger ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Ecosystem Functioning ◽

Biological Diversity ◽

Phenotypic Diversity ◽

Epigenetic Variation ◽

Plant Populations ◽

Natural Plant ◽

Copy Numbers ◽

Diversity Effects

AbstractAn accumulating body of evidence indicates that natural plant populations harbour a large diversity of transposable elements (TEs). TEs provide genetic and epigenetic variation that can substantially translate into changes in plant phenotypes. Despite the wealth of data on the ecological and evolutionary effects of TEs on plant individuals, we have virtually no information on the role of TEs on populations and ecosystem functioning. On the example of Arabidopsis thaliana, we demonstrate that TE-generated variation creates differentiation in ecologically important functional traits. In particular, we show that Arabidopsis populations with increasing diversity of individuals differing in copy numbers of the ONSEN retrotransposon had higher phenotypic and functional diversity. Moreover, increased diversity enhanced population productivity and reduced performance of interspecific competitors. We conclude that TE-generated diversity can have similar effects on ecosystem as usually documented for other biological diversity effects.

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The Boundary-Expressed EPIDERMAL PATTERNING FACTOR-LIKE2 Gene Encoding a Signaling Peptide Promotes Cotyledon Growth during Arabidopsis thaliana Embryogenesis

10.1101/2021.04.27.441542 ◽

2021 ◽

Author(s):

Rina Fujihara ◽

Naoyuki Uchida ◽

Toshiaki Tameshige ◽

Nozomi Kawamoto ◽

Yugo Hotokezaka ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Plant Growth ◽

Mutant Embryo ◽

Loss Of Function ◽

Auxin Response ◽

Gene Encoding ◽

Late Embryogenesis ◽

Signaling Center ◽

Epidermal Patterning

AbstractThe shoot organ boundaries have important roles in plant growth and morphogenesis. It has been reported that a gene encoding a cysteine-rich secreted peptide of the EPIDERMAL PATTERNING FACTOR-LIKE (EPFL) family, EPFL2, is expressed in the boundary domain between the two cotyledon primordia of Arabidopsis thaliana embryo. However, its developmental functions remain unknown. This study aimed to analyze the role of EPFL2 during embryogenesis. We found that cotyledon growth was reduced in its loss-of-function mutants, and this phenotype was associated with the reduction of auxin response peaks at the tips of the primordia. The reduced cotyledon size of the mutant embryo recovered in germinating seedlings, indicating the presence of a factor that acted redundantly with EPFL2 to promote cotyledon growth in late embryogenesis. Our analysis indicates that the boundary domain between the cotyledon primordia acts as a signaling center that organizes auxin response peaks and promotes cotyledon growth.

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Multiple independent recombinations led to hermaphroditism in grapevine

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2023548118 ◽

2021 ◽

Vol 118 (15) ◽

pp. e2023548118

Author(s):

Cheng Zou ◽

Mélanie Massonnet ◽

Andrea Minio ◽

Sagar Patel ◽

Victor Llaca ◽

...

Keyword(s):

Divergence Time ◽

High Linkage Disequilibrium ◽

Recombination Suppression ◽

Wild Grape ◽

Wild Grapevine ◽

Drastic Increase ◽

In The Wild ◽

Additional Support ◽

Female Flowers

Hermaphroditic (perfect) flowers were a key trait in grapevine domestication, enabling a drastic increase in yields due to the efficiency of self-pollination in the domesticated grapevine (Vitis vinifera L. ssp. vinifera). In contrast, all extant wild Vitis species are dioecious, each plant having only male or female flowers. In this study, we identified the male (M) and female (f) haplotypes of the sex-determining region (SDR) in the wild grapevine species V. cinerea and confirmed the boundaries of the SDR. We also demonstrated that the SDR and its boundaries are precisely conserved across the Vitis genus using shotgun resequencing data of 556 wild and domesticated accessions from North America, East Asia, and Europe. A high linkage disequilibrium was found at the SDR in all wild grape species, while different recombination signatures were observed along the hermaphrodite (H) haplotype of 363 cultivated accessions, revealing two distinct H haplotypes, named H1 and H2. To further examine the H2 haplotype, we sequenced the genome of two grapevine cultivars, 'Riesling' and 'Chardonnay'. By reconstructing the first two H2 haplotypes, we estimated the divergence time between H1 and H2 haplotypes at ∼6 million years ago, which predates the domestication of grapevine (∼8,000 y ago). Our findings emphasize the important role of recombination suppression in maintaining dioecy in wild grape species and lend additional support to the hypothesis that at least two independent recombination events led to the reversion to hermaphroditism in grapevine.

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PUCHI Regulates Giant Cell Morphology During Root-Knot Nematode Infection in Arabidopsis thaliana

Frontiers in Plant Science ◽

10.3389/fpls.2021.755610 ◽

2021 ◽

Vol 12 ◽

Author(s):

Reira Suzuki ◽

Mizuki Yamada ◽

Takumi Higaki ◽

Mitsuhiro Aida ◽

Minoru Kubo ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Cell Wall ◽

Genetic Regulation ◽

Three Dimensional ◽

Acid Synthesis ◽

Giant Cells ◽

Loss Of Function ◽

Wild Type ◽

Root Knot Nematode ◽

In The Wild

Parasitic root-knot nematodes transform the host’s vascular cells into permanent feeding giant cells (GCs) to withdraw nutrients from the host plants. GCs are multinucleated metabolically active cells with distinctive cell wall structures; however, the genetic regulation of GC formation is largely unknown. In this study, the functions of the Arabidopsis thaliana transcription factor PUCHI during GC development were investigated. PUCHI expression was shown to be induced in early developing galls, suggesting the importance of the PUCHI gene in gall formation. Despite the puchi mutant not differing significantly from the wild type in nematode invasion and reproduction rates, puchi GC cell walls appeared to be thicker and lobate when compared to the wild type, while the cell membrane sometimes formed invaginations. In three-dimensional (3D) reconstructions of puchi GCs, they appeared to be more irregularly shaped than those in the wild type, with noticeable cell-surface protrusions and folds. Interestingly, the loss-of-function mutant of 3-KETOACYL-COA SYNTHASE 1 showed GC morphology and cell wall defects similar to those of the puchi mutant, suggesting that PUCHI may regulate GC development via very long chain fatty acid synthesis.

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MIR822 modulates monosporic female gametogenesis through an ARGONAUTE9-dependent pathway in Arabidopsis thaliana

10.1101/2021.10.18.464879 ◽

2021 ◽

Author(s):

ANDREA TOVAR AGUILAR ◽

Daniel GRIMANELLI ◽

Gerardo Acosta Garcia ◽

Jean Philippe Vielle Calzada ◽

Jesus Agustin Badillo-Corona ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Molecular Mechanisms ◽

Target Genes ◽

Flowering Plants ◽

Loss Of Function ◽

Genes Encoding ◽

Functional Megaspore ◽

Dependent Pathway ◽

Female Gametogenesis

In the ovule of flowering plants, the establishment of the haploid generation occurs when a somatic cell differentiates into a Megaspore Mother Cell (MMC) and initiates meiosis. As most flowering plants, Arabidopsis thaliana undergoes a monosporic type of gametogenesis; three meiotically derived cells degenerate without further division, and a single one, the functional megaspore (FM), divides mitotically to form the female gametophyte. In Arabidopsis, the ARGONAUTE4 clade proteins are involved in the control of megasporogenesis. In particular, mutations in ARGONAUTE9 (AGO9) lead to the ectopic differentiation of gametic precursors that can give rise female gametophytes. However, the genetic basis and molecular mechanisms that control monosporic gametogenesis remain largely unknown. Here, we show that Arabidopsis plants carrying loss-of-function mutations in the AGO9-interacting miR822a give rise to extranumerary surviving megaspores that acquire a FM identity and divide without giving rise to differentiated female gametophytes. The overexpression of three miR822a target genes encoding Cysteine/Histidine-Rich C1 domain proteins (DC1) phenocopy mir822a plants. The miR822a targets are overexpressed in ago9 mutant ovules, confirming that miR822a acts through an AGO9-dependent pathway to negatively regulate DC1 domain proteins. Our results identify a new role of miRNAs in the most prevalent form of female gametogenesis in flowering plants

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P2K1 Receptor, Heterotrimeric Gα Protein and CNGC2/4 Are Involved in Extracellular ATP-Promoted Ion Influx in the Pollen of Arabidopsis thaliana

Plants ◽

10.3390/plants10081743 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1743

Author(s):

Yansheng Wu ◽

Hongmin Yin ◽

Xinyue Liu ◽

Jiawei Xu ◽

Baozhi Qin ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Pollen Grains ◽

Extracellular Atp ◽

Loss Of Function ◽

Promoting Effect ◽

Α Subunit ◽

Tobacco Pollen ◽

Ion Influx ◽

Signaling Components

As an apoplastic signal, extracellular ATP (eATP) is involved in plant growth and development. eATP promotes tobacco pollen germination (PG) and pollen tube growth (PTG) by stimulating Ca2+ or K+ absorption. Nevertheless, the mechanisms underlying eATP-stimulated ion uptake and their role in PG and PTG are still unclear. Here, ATP addition was found to modulate PG and PTG in 34 plant species and showed a promoting effect in most of these species. Furthermore, by using Arabidopsis thaliana as a model, the role of several signaling components involved in eATP-promoted ion (Ca2+, K+) uptake, PG, and PTG were investigated. ATP stimulated while apyrase inhibited PG and PTG. Patch-clamping results showed that ATP promoted K+ and Ca2+ influx into pollen protoplasts. In loss-of-function mutants of P2K1 (dorn1-1 and dorn1-3), heterotrimeric G protein α subunit (gpa1-1, gpa1-2), or cyclic nucleotide gated ion channel (cngc2, cngc4), eATP-stimulated PG, PTG, and ion influx were all impaired. Our results suggest that these signaling components may be involved in eATP-promoted PG and PTG by regulating Ca2+ or K+ influx in Arabidopsis pollen grains.

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Arabidopsis NF-YCs play dual roles in repressing brassinosteroid biosynthesis and signaling during light-regulated hypocotyl elongation

The Plant Cell ◽

10.1093/plcell/koab112 ◽

2021 ◽

Author(s):

Wenbin Zhang ◽

Yang Tang ◽

Yilong Hu ◽

Yuhua Yang ◽

Jiajia Cai ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Signaling Pathway ◽

Growth Regulators ◽

Nuclear Factor ◽

Loss Of Function ◽

Hypocotyl Growth ◽

Dual Roles ◽

Environmental Stimulus ◽

Biosynthesis Gene

Abstract Light functions as the primary environmental stimulus and brassinosteroids (BRs) as important endogenous growth regulators throughout the plant lifecycle. Photomorphogenesis involves a series of vital developmental processes that require the suppression of BR-mediated seedling growth, but the mechanism underlying the light-controlled regulation of the BR pathway remain unclear. Here, we reveal that nuclear factor YC proteins (NF-YCs) function as essential repressors of the BR pathway during light-controlled hypocotyl growth in Arabidopsis thaliana. In the light, NF-YCs inhibit BR biosynthesis by directly targeting the promoter of the BR biosynthesis gene BR6ox2 and repressing its transcription. NF-YCs also interact with BIN2, a critical repressor of BR signaling, and facilitate its stabilization by promoting its Tyr200 autophosphorylation, thus inhibiting the BR signaling pathway. Consistently, loss-of-function mutants of NF-YCs show etiolated growth and constitutive BR responses, even in the light. Our findings uncover a dual role of NF-YCs in repressing BR biosynthesis and signaling, providing mechanistic insights into how light antagonizes the BR pathway to ensure photomorphogenic growth in Arabidopsis.

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ATANN3 is involved in extracellular ATP-regulated auxin transport and distribution in Arabidopsis thaliana seedlings

10.21203/rs.3.rs-841741/v1 ◽

2021 ◽

Author(s):

Lijuan Han ◽

Shuyan Xia ◽

Jiawei Xu ◽

Ruojia Zhu ◽

Zhonglin Shang ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Stress Responses ◽

Auxin Transport ◽

Inhibitory Effect ◽

Extracellular Atp ◽

Root Tip ◽

Asymmetric Distribution ◽

Loss Of Function ◽

Hypocotyl Growth

Abstract Background Extracellular ATP (eATP) exists in the apoplast of plants and plays multiple roles in growth, development, and stress responses. It has been reported that eATP stimulation suppresses growth rate and alters growth orientation of root and hypocotyls of Arabidopsis thaliana seedlings by affecting auxin accumulation and transport in these organs. However, the mechanism of eATP-stimulated vegetative organ growth remains unclear. Annexins are involved in multiple aspects of plant cellular metabolism, while the role of annexins in response to apoplast signal remains unclear. Here, by using loss-of-function mutants, we investigated the role of several annexins in eATP-regulated root and hypocotyl growth. Since mutant of AtANN3 did not respond to eATP sensitively, the role of AtANN3 in eATP regulated auxin transport was intensively investigated. Results First, the inhibitory effect of eATP on root or hypocotyl elongation was weakened or impaired in AtANN3 null mutants (atann3). Meanwhile, single-, double- or triple-null mutant of AtANN1, AtANN2 or AtANN4 responded to eATP stimulation in same manner and degree with Col-0. The abundance and distribution of Dr5-GUS and Dr5-GFP indicated that eATP-induced accumulation and asymmetric distribution of auxin in root tip or hypocotyl cells, which appeared in wild type controls, were lacking in atann3 seedlings. Further, eATP-induced accumulation and asymmetric distribution of PIN2-GFP in root tip cells or PIN3-GFP in hypocotyl cells were reduced in atann3 seedlings. Conclusions AtANN3 may be involved in eATP-regulated seedling growth through regulating auxin transport and accumulation in vegetative organs.

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Heterotrimeric G-proteins involved in the MeJA regulated ion flux and stomatal closure in Arabidopsis thaliana

Functional Plant Biology ◽

10.1071/fp14162 ◽

2015 ◽

Vol 42 (2) ◽

pp. 126 ◽

Cited By ~ 8

Author(s):

Suli Yan ◽

Shuitian Luo ◽

Shanshan Dong ◽

Ting Zhang ◽

Jingru Sun ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

G Proteins ◽

Stomatal Closure ◽

Guard Cells ◽

Ion Flux ◽

Heterotrimeric G Proteins ◽

Loss Of Function ◽

Test Technique ◽

In The Wild ◽

Pre Treatment

Heterotrimeric G-proteins play an important role in plant signalling pathways. The plant hormone methyl jasmonate (MeJA) can induce stomatal closure in many plant species. The signal cascade in MeJA-induced stomatal closure has been studied previously. However, the function of G proteins in this process has not yet been evaluated. In this study, the stomatal movement induced by MeJA in the wild-type Arabidopsis thaliana (L. Heynh.) (WS), Gα subunit loss-of-function mutant gpa1–1 and gpa1–2 guard cells were measured. Further, the transmembrane ion flux (H+, Ca2+ and K+) and reactive oxygen species (ROS) experiments were performed in guard cells from WS, GDP-β-S pre-treated WS, gpa1–1 and gpa1–2 using non-invasive micro-test technique (NMT) and confocal technique. It was observed that the MeJA-induced stomatal closure was abolished in guard cells of gpa1 mutants. GDP-β-S pre-treatment and gpa1 mutants impaired the MeJA-activated H+ efflux, Ca2+ influx and K+ efflux. The accumulation of ROS in gpa1–1 and gpa1–2 guard cells was also lower than that in WS guard cells under MeJA treatment. These results suggested that Gα subunits are involved in regulating the signal events in JA signal pathway and stomatal closure.

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Developmental genetics of corolla tube formation: role of the tasiRNA-ARF pathway and a conceptual model

10.1101/253112 ◽

2018 ◽

Cited By ~ 1

Author(s):

Baoqing Ding ◽

Rui Xia ◽

Qiaoshan Lin ◽

Vandana Gurung ◽

Janelle M. Sagawa ◽

...

Keyword(s):

Conceptual Model ◽

Critical Role ◽

Corolla Tube ◽

Tube Formation ◽

Developmental Genetics ◽

Loss Of Function ◽

Auxin Distribution ◽

In The Wild ◽

Corolla Tube Formation

ABSTRACTMore than 80,000 angiosperm species produce flowers with petals fused into a corolla tube. As an important element of the tremendous diversity of flower morphology, the corolla tube plays a critical role in many specialized interactions between plants and animal pollinators (e.g., beeflies, hawkmoths, hummingbirds, nectar bats), which in turn drives rapid plant speciation. Despite its clear significance in plant reproduction and evolution, the corolla tube remains one of the least understood plant structures from a developmental genetics perspective. Through mutant analyses and transgenic experiments, here we show that the tasiRNA-ARF pathway is required for corolla tube formation in the monkeyflower species Mimulus lewisii. Loss-of-function mutations in the M. lewisii orthologs of ARGONAUTE7 and SUPPRESSOR OF GENE SILENCING 3 cause a dramatic decrease in abundance of TAS3-derived small RNAs and a moderate up-regulation of AUXIN RESPONSE FACTOR 3 (ARF3) and ARF4, which lead to inhibition of lateral expansion of the bases of petal primordia and complete arrest of the upward growth of the inter-primordial regions, resulting in unfused corollas. By using an auxin reporter construct, we discovered that auxin distribution is continuous along the petal primordium base and the inter-primordial region during the critical stage of corolla tube formation in the wild-type, and that this auxin distribution is much weaker and more restricted in the mutant. Together, these results suggest a new conceptual model highlighting the central role of auxin directed synchronized growth of the petal primordium base and the inter-primordial region in corolla tube formation.

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