The plant hormone ethylene plays various functions in plant growth, development and response to environmental stress. Ethylene is perceived by membranebound ethylene receptors, and among the homologous receptors in Ar...The plant hormone ethylene plays various functions in plant growth, development and response to environmental stress. Ethylene is perceived by membranebound ethylene receptors, and among the homologous receptors in Arabidopsis, the ETR1 ethylene receptor plays a major role. The present study provides evidence demonstrating that Arabidopsis CPR5 functions as a novel ETR1 receptor-interacting protein in regulating ethylene response and signaling. Yeast split ubiquitin assays and bifluorescence complementation studies in plant cells indicated that CPR5 directly interacts with the ETR1 receptor. Genetic analyses indicated that mutant alleles of cpr5 can suppress ethylene insensitivity in both etr1-1 and etr1-2, but not in other dominant ethylene receptormutants. Overexpression of Arabidopsis CPR5 either in transgenic Arabidopsis plants, or ectopically in tobacco,significantly enhanced ethylene sensitivity. These findings indicate that CPR5 plays a critical role in regulating ethylene signaling. CPR5 is localized to endomembrane structures and the nucleus, and is involved in various regulatory pathways, including pathogenesis, leaf senescence, and spontaneous cell death. This study provides evidence for a novel regulatory function played by CPR5 in the ethylene receptor signaling pathway in Arabidopsis.展开更多
A mango ETHYLENE RESPONSE1(ETR1) gene, designated Mi ETR1 b, was isolated from the cotyledon of mango(Mangifera indica L. ‘Zihua')using RT-PCR, and the 5′ and 3′ rapid amplificatio of c DNA ends. The full-lengt...A mango ETHYLENE RESPONSE1(ETR1) gene, designated Mi ETR1 b, was isolated from the cotyledon of mango(Mangifera indica L. ‘Zihua')using RT-PCR, and the 5′ and 3′ rapid amplificatio of c DNA ends. The full-length c DNA was 2 530 bp, with an open reading frame of 2 220 bp,and it encoded a putative protein of 739 amino acids. The genomic DNA sequence of Mi ETR1 b was 4 116 bp in length, having a 3 305 bp sequence from the start to terminator codon, containing six exons and fi e introns. The deduced amino acids possessed conserved domains of the GAF and HATPase_c superfamilies. A phylogenetic tree analysis indicated that Mi ETR1 b had the highest similarity to Mi ETR1 from M. indica and a high similarity to Cs ERS1, Dl ETR1, Tc ERS1 and Pt ETR1. Quantitative real-time PCR showed that Mi ETR1 b was expressed in the proximal and distal cut surfaces throughout the adventitious root formation period. Meanwhile, the expression of Mi ETR1 b in the distal cut surface was significant y up-regulated within 6–48 h. Pre-treatments with indole-3-butyric acid and 2,3,5-triiodobenzoic acid significant y downregulated Mi ETR1 b expression at 1 d and 6 h, respectively. However, more ethylene was produced from 12 to 24 h, while ethylene production decreased after 4 days of culturing. In conclusion, Mi ETR1 b might play an important role during the adventitious root formation of mango cotyledon segments, which is related to ethylene production.展开更多
ETHYLENE INSENSITIVE2(EIN2)is a key component of ethylene signaling whose activity is inhibited upon phosphorylation of Ser^(645) and Ser^(924) by the Raf-like CONSTITUTIVE TRIPLE-RESPONSE 1(CTR1)in the absence of eth...ETHYLENE INSENSITIVE2(EIN2)is a key component of ethylene signaling whose activity is inhibited upon phosphorylation of Ser^(645) and Ser^(924) by the Raf-like CONSTITUTIVE TRIPLE-RESPONSE 1(CTR1)in the absence of ethylene.Ethylene prevents CTR1 activity and thus EIN2^(Ser645/Ser924) phosphorylation,and subcellular trafficking of a proteolytically cleaved EIN2 C terminus(EIN2-C)from the endoplasmic reticulum to the nucleus and processing bodies triggers ethylene signaling.Here,we report an unexpected complexity of EIN2-activated ethylene signaling.EIN2 activation in part requires ethylene in the absence of CTR1-mediated negative regulation.The ein2 mutant was complemented by the transgenes encoding EIN2,EIN2 variants with mutations that either prevent or mimic Ser^(645)/Ser^(924) phosphorylation,or EIN2-C;and all the transgenic lines carrying these EIN2-derived transgenes responded to ethylene.Furthermore,we found that the fluorescence protein-tagged EIN2 and its variants were affected little by ethylene and exhibited similar subcellular distribution patterns:in the cytosolic particles and nuclear speckles.Of note,the subcellular localization patterns of EIN2 proteins fused with a fluorescence protein either at the N or C terminus were similar,whereas EIN2-C-YFP was primarily observed in the cytosol but not in the nucleus.Western blots and mass spectrum analyses suggested a high complexity of EIN2,which is likely proteolytically processed into multiple fragments.Our results suggested a nuclear localization of the full-length EIN2,weak association of the EIN2^(Ser645/Ser924) phosphorylation status and ethylene signaling,and the complexity of ethylene signaling caused by EIN2 and its proteolytic products in different subcellular compartments.We propose an alternative model to explain EIN2-activated ethylene signaling.展开更多
基金supported by the National Natural Science Foundation of China (31370322)the Shandong Development Program for Science and Technology (2015GNC110012) to CHD+1 种基金the National Natural Science Foundation of China (31400247) to HPa grant from the National Institutes of Health 1R01GM071855 to CC
文摘The plant hormone ethylene plays various functions in plant growth, development and response to environmental stress. Ethylene is perceived by membranebound ethylene receptors, and among the homologous receptors in Arabidopsis, the ETR1 ethylene receptor plays a major role. The present study provides evidence demonstrating that Arabidopsis CPR5 functions as a novel ETR1 receptor-interacting protein in regulating ethylene response and signaling. Yeast split ubiquitin assays and bifluorescence complementation studies in plant cells indicated that CPR5 directly interacts with the ETR1 receptor. Genetic analyses indicated that mutant alleles of cpr5 can suppress ethylene insensitivity in both etr1-1 and etr1-2, but not in other dominant ethylene receptormutants. Overexpression of Arabidopsis CPR5 either in transgenic Arabidopsis plants, or ectopically in tobacco,significantly enhanced ethylene sensitivity. These findings indicate that CPR5 plays a critical role in regulating ethylene signaling. CPR5 is localized to endomembrane structures and the nucleus, and is involved in various regulatory pathways, including pathogenesis, leaf senescence, and spontaneous cell death. This study provides evidence for a novel regulatory function played by CPR5 in the ethylene receptor signaling pathway in Arabidopsis.
基金financial y supported by the National Natural Science Foundation of China(31372053)
文摘A mango ETHYLENE RESPONSE1(ETR1) gene, designated Mi ETR1 b, was isolated from the cotyledon of mango(Mangifera indica L. ‘Zihua')using RT-PCR, and the 5′ and 3′ rapid amplificatio of c DNA ends. The full-length c DNA was 2 530 bp, with an open reading frame of 2 220 bp,and it encoded a putative protein of 739 amino acids. The genomic DNA sequence of Mi ETR1 b was 4 116 bp in length, having a 3 305 bp sequence from the start to terminator codon, containing six exons and fi e introns. The deduced amino acids possessed conserved domains of the GAF and HATPase_c superfamilies. A phylogenetic tree analysis indicated that Mi ETR1 b had the highest similarity to Mi ETR1 from M. indica and a high similarity to Cs ERS1, Dl ETR1, Tc ERS1 and Pt ETR1. Quantitative real-time PCR showed that Mi ETR1 b was expressed in the proximal and distal cut surfaces throughout the adventitious root formation period. Meanwhile, the expression of Mi ETR1 b in the distal cut surface was significant y up-regulated within 6–48 h. Pre-treatments with indole-3-butyric acid and 2,3,5-triiodobenzoic acid significant y downregulated Mi ETR1 b expression at 1 d and 6 h, respectively. However, more ethylene was produced from 12 to 24 h, while ethylene production decreased after 4 days of culturing. In conclusion, Mi ETR1 b might play an important role during the adventitious root formation of mango cotyledon segments, which is related to ethylene production.
基金supported by the National Natural Science Foundation of China(31570277 and 31770302)Chinese Academy of Sciences(XDB27030208).
文摘ETHYLENE INSENSITIVE2(EIN2)is a key component of ethylene signaling whose activity is inhibited upon phosphorylation of Ser^(645) and Ser^(924) by the Raf-like CONSTITUTIVE TRIPLE-RESPONSE 1(CTR1)in the absence of ethylene.Ethylene prevents CTR1 activity and thus EIN2^(Ser645/Ser924) phosphorylation,and subcellular trafficking of a proteolytically cleaved EIN2 C terminus(EIN2-C)from the endoplasmic reticulum to the nucleus and processing bodies triggers ethylene signaling.Here,we report an unexpected complexity of EIN2-activated ethylene signaling.EIN2 activation in part requires ethylene in the absence of CTR1-mediated negative regulation.The ein2 mutant was complemented by the transgenes encoding EIN2,EIN2 variants with mutations that either prevent or mimic Ser^(645)/Ser^(924) phosphorylation,or EIN2-C;and all the transgenic lines carrying these EIN2-derived transgenes responded to ethylene.Furthermore,we found that the fluorescence protein-tagged EIN2 and its variants were affected little by ethylene and exhibited similar subcellular distribution patterns:in the cytosolic particles and nuclear speckles.Of note,the subcellular localization patterns of EIN2 proteins fused with a fluorescence protein either at the N or C terminus were similar,whereas EIN2-C-YFP was primarily observed in the cytosol but not in the nucleus.Western blots and mass spectrum analyses suggested a high complexity of EIN2,which is likely proteolytically processed into multiple fragments.Our results suggested a nuclear localization of the full-length EIN2,weak association of the EIN2^(Ser645/Ser924) phosphorylation status and ethylene signaling,and the complexity of ethylene signaling caused by EIN2 and its proteolytic products in different subcellular compartments.We propose an alternative model to explain EIN2-activated ethylene signaling.
