Release of GTP Exchange Factor Mediated Down-Regulation of Abscisic Acid Signal Transduction through ABA-Induced Rapid Degradation of RopGEFs

Li, Zixing; Waadt, Rainer; Schroeder, Julian I.

doi:10.1371/journal.pbio.1002461

Cited by 56 publications

(61 citation statements)

References 81 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The small GTPase ROP11 interacts with and protects ABI1 from inhibition by PYL9 (Li et al, 2012). In turn, ABI1 and the other PP2Cs protect the GTP exchange factor RopGEF1 from ABA-induced degradation, thus forming a RopGEF-ROP-PP2C control loop that may counteract leaky ABA signaling by monomeric PYLs in the absence of stress (Li et al, 2016). …”

Section: Aba Signalingmentioning

confidence: 99%

Abiotic Stress Signaling and Responses in Plants

Zhu

2016

Cell

3,987

2,749

View full text Add to dashboard Cite

Summary As sessile organisms, plants must cope with abiotic stress such as soil salinity, drought, and extreme temperatures. Core stress signaling pathways involve protein kinases related to the yeast SNF1 and mammalian AMPK, suggesting that stress signaling in plants evolved from energy sensing. Stress signaling regulates proteins critical for ion and water transport and for metabolic and gene-expression reprogramming to bring about ionic and water homeostasis and cellular stability under stress conditions. Understanding stress signaling and responses will increase our ability to improve stress resistance in crops to achieve agricultural sustainability and food security for a growing world population.

show abstract

Section: Aba Signalingmentioning

confidence: 99%

Abiotic Stress Signaling and Responses in Plants

Zhu

2016

Cell

3,987

2,749

View full text Add to dashboard Cite

show abstract

“…Hypersensitive responses to abscisic acid (ABA)-mediated stomata closure and ABA-inhibited root growth have been reported for ropgef1ropgef4 and ropgef1ropgef4ropgef10 mutant plants (Li and Liu, 2012;Yu et al, 2012). A recent study found that RopGEF1 was targeted for degradation by ABA and functioned in ABA-mediated inhibition of lateral root growth (Li et al, 2016). RopGEF11 has been shown to be involved in root development by interacting with phytochrome (Shin et al, 2010).…”

mentioning

confidence: 99%

RopGEF1 Plays a Critical Role in Polar Auxin Transport in Early Development

et al. 2017

View full text Add to dashboard Cite

Polar auxin transport, facilitated by the combined activities of auxin influx and efflux carriers to maintain asymmetric auxin distribution, is essential for plant growth and development. Here, we show that Arabidopsis (Arabidopsis thaliana) RopGEF1, a guanine nucleotide exchange factor and activator of Rho GTPases of plants (ROPs), is critically involved in polar distribution of auxin influx carrier AUX1 and differential accumulation of efflux carriers PIN7 and PIN2 and is important for embryo and early seedling development when RopGEF1 is prevalently expressed. Knockdown or knockout of RopGEF1 induces embryo defects, cotyledon vein breaks, and delayed root gravity responses. Altered expression from the auxin response reporter DR5rev:GFP in the root pole of RopGEF1-deficient embryos and loss of asymmetric distribution of DR5rev:GFP in their gravistimulated root tips suggest that auxin distribution is affected in ropgef1 mutants. This is reflected by the polarity of AUX1 being altered in ropgef1 embryos and roots, shifting from the normal apical membrane location to a basal location in embryo central vascular and root protophloem cells and also reduced PIN7 accumulation at embryos and altered PIN2 distribution in gravistimulated roots of mutant seedlings. In establishing that RopGEF1 is critical for AUX1 localization and PIN differential accumulation, our results reveal a role for RopGEF1 in cell polarity and polar auxin transport whereby it imapcts auxin-mediated plant growth and development.

show abstract

“…The deduced amino acid sequence of KAR encodes a highly conserved plant-specific Rop nucleotide exchanger (PRONE) catalytic domain, which is characteristic of the guanine nucleotide exchange factor (GEF) of the Rop GTPase [19], while the N- and C-terminal regions outside of the PRONE domain were highly variable (Figure S3). In angiosperms, Rop signaling mediated by RopGEF is involved in various developmental processes and environmental responses [20–25]. KAR is the sole PRONE-type RopGEF gene in the M. polymorpha genome.…”

Section: Resultsmentioning

confidence: 99%

The RopGEF KARAPPO is Essential for the Initiation of Vegetative Reproduction in Marchantia

Hiwatashi

Quan

Yasui

et al. 2018

Preprint

View full text Add to dashboard Cite

22 23 24 Manuscript SUMMARY 25 Many plants can reproduce vegetatively, producing clonal progeny from vegetative cells; 26 however, little is known about the molecular mechanisms underlying this process. 27 Liverwort (Marchantia polymorpha), a basal land plant, propagates asexually via gemmae, 28 which are clonal plantlets formed in gemma cups on the dorsal side of the vegetative 29 thallus [1]. The initial stage of gemma development involves elongation and asymmetric 30divisions of a specific type of epidermal cell, called a gemma initial, which forms on the 31 floor of the gemma cup [2, 3]. To investigate the regulatory mechanism underlying gemma 32 development, we focused on two allelic mutants in which no gemma initial formed; these 33 mutants were named karappo, meaning "empty". We used whole-genome sequencing of 34 both mutants, and molecular genetic analyses to identify the causal gene, KARAPPO (KAR), 35 which encodes a Rop guanine nucleotide exchange factor (RopGEF) carrying a PRONE 36 catalytic domain. In vitro GEF assays showed that the full-length KAR protein and the 37 PRONE domain have significant GEF activity toward MpRop, the only Rop GTPase in M. 38 polymorpha. Moreover, genetic complementation experiments showed a significant role for 39 the N-and C-terminal variable regions in gemma development. Our investigation 40 demonstrated an essential role for KAR/RopGEF in the initiation of plantlet development 41 from a differentiated cell, which may involve cell polarity formation and subsequent 42 asymmetric cell division via activation of Rop signaling, implying a similar developmental 43 mechanism in vegetative reproduction of various land plants.44 45 KEYWORDS 46 asexual reproduction, small GTPase, cell polarity, evolution 47 48 3 RESULTS AND DISCUSSION 49 Gemma development in Marchantia polymorpha 50 Vegetative reproduction is a form of asexual reproduction in which clonal individuals 51 develop directly from vegetative tissues, such as leaves, stems, and roots. Vegetative 52 reproduction is a developmental process based on totipotency, which is the potential for a 53 cell, even a differentiated cell, to regenerate organs or whole plantlets [4-6]. Many plants in 54 diverse lineages exhibit vegetative reproduction, e.g. potato (Solanum tuberosum), which 55 produces tubers in underground stems, Kalanchoe diagremontiana, which forms plantlets 56 at the leaf margins, the Dhalia family, which develop root tubers, and the hen and chicken 57 fern (Asplennium bulbiferum), which grows small bulbils on the top of fronds [7]. However, 58 very little is known about the underlying molecular mechanisms of vegetative 59 reproduction. 60 One of the most basal lineages in extant land plants, the liverwort Marchantia 61 polymorpha, has the ability to propagate asexually by forming clonal plantlets, called 62 gemmae, in a cupule or "gemma cup", a cup-like receptacle formed on the dorsal side of 63 the thallus, which is the gametophyte plant body (Figure S1A). The development of the 64 gemma and gemma cup in M. pol...

show abstract

Release of GTP Exchange Factor Mediated Down-Regulation of Abscisic Acid Signal Transduction through ABA-Induced Rapid Degradation of RopGEFs

Cited by 56 publications

References 81 publications

Abiotic Stress Signaling and Responses in Plants

Abiotic Stress Signaling and Responses in Plants

RopGEF1 Plays a Critical Role in Polar Auxin Transport in Early Development

The RopGEF KARAPPO is Essential for the Initiation of Vegetative Reproduction in Marchantia

Contact Info

Product

Resources

About