A Gγ subunit promoter T-DNA insertion mutant—A1-412 of Magnaporthe grisea is defective in appressorium formation, penetration and pathogenicity

2006 ◽  
Vol 51 (18) ◽  
pp. 2214-2218 ◽  
Author(s):  
Shen Liang ◽  
Zhengyi Wang ◽  
Pengjuan Liu ◽  
Debao Li
Keyword(s):  
Magnaporthe Grisea ◽  
Insertion Mutant ◽  
Appressorium Formation ◽  
Dna Insertion

scholarly journals Inhibition of Fungal Appressorium Formation by Pepper (Capsicum annuum) Esterase

2001 ◽  
Vol 14 (1) ◽  
pp. 80-85 ◽  
Author(s):  
Young Soon Kim ◽  
Hyun Hwa Lee ◽  
Moon Kyung Ko ◽  
Chae Eun Song ◽  
Cheol-Yong Bae ◽  
...  
Keyword(s):  
Recombinant Protein ◽  
Capsicum Annuum ◽  
Magnaporthe Grisea ◽  
Dependent Manner ◽  
Appressorium Formation ◽  
Glutathione S Transferase ◽  
Porcine Liver ◽  
Esterase Gene ◽  
Dose Dependent ◽  
Dependent Signaling Pathway

A pepper esterase gene (PepEST) that is highly expressed during an incompatible interaction between pepper (Capsicum annuum) and the anthracnose fungus Colletotrichum gloeosporioides has been previously cloned. Glutathione-S-transferase-tagged recombinant PepEST protein expressed in Escherichia coli showed substrate specificity for p-nitrophenyl esters. Inoculation of compatible unripe pepper fruits with C. gloeosporioides spores amended with the recombinant protein did not cause anthracnose symptoms on the fruit. The recombinant protein has no fungicidal activity, but it significantly inhibits appressorium formation of the anthracnose fungus in a dose-dependent manner. An esterase from porcine liver also inhibited appressorium formation, and the recombinant protein inhibited appressorium formation in the rice blast fungus, Magnaporthe grisea. Inhibition of appressorium formation in M. grisea by the recombinant protein was reversible by treatment with cyclic AMP (cAMP) or 1,16-hexadecanediol. The results suggest that the recombinant protein regulates appressorium formation by modulating the cAMP-dependent signaling pathway in this fungus. Taken together, the PepEST esterase activity can inhibit appressorium formation of C. gloeosporioides, which may result in protection of the unripe fruit against the fungus.

scholarly journals A unique AtSar1D-AtRabD2a nexus modulates autophagosome biogenesis in Arabidopsis thaliana

2021 ◽  
Vol 118 (17) ◽  
pp. e2021293118
Author(s):  
Yonglun Zeng ◽  
Baiying Li ◽  
Changyang Ji ◽  
Lei Feng ◽  
Fangfang Niu ◽  
...  
Keyword(s):  
Stress Responses ◽  
Higher Plants ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Secretory Proteins ◽  
Insertion Mutant ◽  
Intermediate Metabolites ◽  
Dna Insertion ◽  
Autophagy Pathway ◽  
Copii Vesicles

In eukaryotes, secretory proteins traffic from the endoplasmic reticulum (ER) to the Golgi apparatus via coat protein complex II (COPII) vesicles. Intriguingly, during nutrient starvation, the COPII machinery acts constructively as a membrane source for autophagosomes during autophagy to maintain cellular homeostasis by recycling intermediate metabolites. In higher plants, essential roles of autophagy have been implicated in plant development and stress responses. Nonetheless, the membrane sources of autophagosomes, especially the participation of the COPII machinery in the autophagic pathway and autophagosome biogenesis, remains elusive in plants. Here, we provided evidence in support of a novel role of a specific Sar1 homolog AtSar1d in plant autophagy in concert with a unique Rab1/Ypt1 homolog AtRabD2a. First, proteomic analysis of the plant ATG (autophagy-related gene) interactome uncovered the mechanistic connections between ATG machinery and specific COPII components including AtSar1d and Sec23s, while a dominant negative mutant of AtSar1d exhibited distinct inhibition on YFP-ATG8 vacuolar degradation upon autophagic induction. Second, a transfer DNA insertion mutant of AtSar1d displayed starvation-related phenotypes. Third, AtSar1d regulated autophagosome progression through specific recognition of ATG8e by a noncanonical motif. Fourth, we demonstrated that a plant-unique Rab1/Ypt1 homolog AtRabD2a coordinates with AtSar1d to function as the molecular switch in mediating the COPII functions in the autophagy pathway. AtRabD2a appears to be essential for bridging the specific AtSar1d-positive COPII vesicles to the autophagy initiation complex and therefore contributes to autophagosome formation in plants. Taken together, we identified a plant-specific nexus of AtSar1d-AtRabD2a in regulating autophagosome biogenesis.

scholarly journals Plastid-Localized EMB2726 Is Involved in Chloroplast Biogenesis and Early Embryo Development in Arabidopsis

2021 ◽  
Vol 12 ◽  
Author(s):  
Chuanling Li ◽  
Jian-Xiu Shang ◽  
Chenlei Qiu ◽  
Baowen Zhang ◽  
Jinxue Wang ◽  
...  
Keyword(s):  
Chloroplast Development ◽  
Developmental Process ◽  
Higher Plants ◽  
Critical Role ◽  
Elongation Factor ◽  
Early Embryo ◽  
The Body ◽  
Insertion Mutant ◽  
Cell Stage ◽  
Dna Insertion

Embryogenesis is a critical developmental process that establishes the body organization of higher plants. During this process, the biogenesis of chloroplasts from proplastids is essential. A failure in chloroplast development during embryogenesis can cause morphologically abnormal embryos or embryonic lethality. In this study, we isolated a T-DNA insertion mutant of the Arabidopsis gene EMBRYO DEFECTIVE 2726 (EMB2726). Heterozygous emb2726 seedlings produced about 25% albino seeds with embryos that displayed defects at the 32-cell stage and that arrested development at the late globular stage. EMB2726 protein was localized in chloroplasts and was expressed at all stages of development, such as embryogenesis. Moreover, the two translation elongation factor Ts domains within the protein were critical for its function. Transmission electron microscopy revealed that the cells in emb2726 embryos contained undifferentiated proplastids and that the expression of plastid genome-encoded photosynthesis-related genes was dramatically reduced. Expression studies of DR5:GFP, pDRN:DRN-GFP, and pPIN1:PIN1-GFP reporter lines indicated normal auxin biosynthesis but altered polar auxin transport. The expression of pSHR:SHR-GFP and pSCR:SCR-GFP confirmed that procambium and ground tissue precursors were lacking in emb2726 embryos. The results suggest that EMB2726 plays a critical role during Arabidopsis embryogenesis by affecting chloroplast development, possibly by affecting the translation process in plastids.

scholarly journals The chaperonin 60 protein SlCpn60α1 modulates photosynthesis and photorespiration in tomato

2020 ◽  
Vol 71 (22) ◽  
pp. 7224-7240
Author(s):  
Jie Ye ◽  
Weifang Chen ◽  
Longwei Feng ◽  
Genzhong Liu ◽  
Ying Wang ◽  
...  
Keyword(s):  
Calvin Cycle ◽  
Photosynthetic Electron Transport ◽  
Single Copy ◽  
Chlorophyll Synthesis ◽  
Insertion Mutant ◽  
Loss Of Function ◽  
Virus Induced Gene Silencing ◽  
Dna Insertion ◽  
Dimensional Electrophoresis ◽  
Two Hybrid

Abstract Photosynthesis, an indispensable biological process of plants, produces organic substances for plant growth, during which photorespiration occurs to oxidize carbohydrates to achieve homeostasis. Although the molecular mechanism underlying photosynthesis and photorespiration has been widely explored, the crosstalk between the two processes remains largely unknown. In this study, we isolated and characterized a T-DNA insertion mutant of tomato (Solanum lycopersicum) named yellow leaf (yl) with yellowish leaves, retarded growth, and chloroplast collapse that hampered both photosynthesis and photorespiration. Genetic and expression analyses demonstrated that the phenotype of yl was caused by a loss-of-function mutation resulting from a single-copy T-DNA insertion in chaperonin 60α1 (SlCPN60α1). SlCPN60α1 showed high expression levels in leaves and was located in both chloroplasts and mitochondria. Silencing of SlCPN60α1using virus-induced gene silencing and RNA interference mimicked the phenotype of yl. Results of two-dimensional electrophoresis and yeast two-hybrid assays suggest that SlCPN60α1 potentially interacts with proteins that are involved in chlorophyll synthesis, photosynthetic electron transport, and the Calvin cycle, and further affect photosynthesis. Moreover, SlCPN60α1 directly interacted with serine hydroxymethyltransferase (SlSHMT1) in mitochondria, thereby regulating photorespiration in tomato. This study outlines the importance of SlCPN60α1 for both photosynthesis and photorespiration, and provides molecular insights towards plant genetic improvement.

Proteome analysis of rice blast fungus (Magnaporthe grisea) proteome during appressorium formation

PROTEOMICS ◽  
2004 ◽  
Vol 4 (11) ◽  
pp. 3579-3587 ◽  
Author(s):  
Sun Tae Kim ◽  
Seok Yu ◽  
Sang Gon Kim ◽  
Han Ju Kim ◽  
Sun Young Kang ◽  
...  
Keyword(s):  
Rice Blast ◽  
Magnaporthe Grisea ◽  
Proteome Analysis ◽  
Rice Blast Fungus ◽  
Appressorium Formation ◽  
Blast Fungus

scholarly journals G Protein α Subunit Genes Control Growth, Development, and Pathogenicity of Magnaporthe grisea

1997 ◽  
Vol 10 (9) ◽  
pp. 1075-1086 ◽  
Author(s):  
Shaohua Liu ◽  
Ralph A. Dean
Keyword(s):  
Neurospora Crassa ◽  
G Protein ◽  
Vegetative Growth ◽  
Magnaporthe Grisea ◽  
Cryphonectria Parasitica ◽  
Appressorium Formation ◽  
Α Subunit ◽  
Targeted Deletion ◽  
Control Growth ◽  
G Protein Α Subunit

Three G protein α subunit genes have been cloned and characterized from Magnaporthe grisea: magA is very similar to CPG-2 of Cryphonectria parasitica; magB is virtually identical to CPG-1 of Cryphonectria parasitica, to gna1 of Neurospora crassa, and to fadA of Emericella nidulans; and magC is most similar to gna2 of Neurospora crassa. Homologous recombination resulting in targeted deletion of magA had no effect on vegetative growth, conidiation, or appressorium formation. Deletion of magC reduced conidiation, but did not affect vegetative growth or appressorium formation. However, disruption of magB significantly reduced vegetative growth, conidiation, and appressorium formation. magB¯ transformants, unlike magA¯ and magC¯ transformants, exhibited a reduced ability to infect and colonize susceptible rice leaves. G protein α subunit genes are required for M. grisea mating. magB¯ transformants failed to form perithecia, whereas magA¯ and magC¯ transformants did not produce mature asci. These results suggest that G protein α subunit genes are involved in signal transduction pathways in M. grisea that control vegetative growth, conidiation, conidium attachment, appressorium formation, mating, and pathogenicity.

scholarly journals Expression of α-DIOXYGENASE 1 in Tomato and Arabidopsis Contributes to Plant Defenses Against Aphids

2013 ◽  
Vol 26 (8) ◽  
pp. 977-986 ◽  
Author(s):  
Carlos Augusto Avila ◽  
Lirio Milenka Arevalo-Soliz ◽  
Argelia Lorence ◽  
Fiona L. Goggin
Keyword(s):  
Green Peach Aphid ◽  
Macrosiphum Euphorbiae ◽  
Insertion Mutant ◽  
Plant Signaling ◽  
Virus Induced Gene Silencing ◽  
Basal Resistance ◽  
Potato Aphid ◽  
Dna Insertion ◽  
Mutant Lines ◽  
Increased Susceptibility

Plant α-dioxygenases (α-DOX) are fatty acid–hydroperoxidases that contribute to the synthesis of oxylipins, a diverse group of compounds primarily generated through oxidation of linoleic (LA) and linolenic acid (LNA). Oxylipins are implicated in plant signaling against biotic and abiotic stresses. We report here that the potato aphid (Macrosiphum euphorbiae) induces Slα-DOX1 but not Slα-DOX2 expression in tomato (Solanum lycopersicum). Slα-DOX1 upregulation by aphids does not require either jasmonic acid (JA) or salicylic acid (SA) accumulation, since tomato mutants deficient in JA (spr2, acx1) or SA accumulation (NahG) still show Slα-DOX1 induction. Virus-induced gene silencing of Slα-DOX1 enhanced aphid population growth in wild-type (WT) plants, revealing that Slα-DOX1 contributes to basal resistance to aphids. Moreover, an even higher percent increase in aphid numbers occurred when Slα-DOX1 was silenced in spr2, a mutant line characterized by elevated LA levels, decreased LNA, and enhanced aphid resistance as compared with WT. These results suggest that aphid reproduction is influenced by oxylipins synthesized from LA by Slα-DOX1. In agreement with our experiments in tomato, two independent α-dox1 T-DNA insertion mutant lines in Arabidopsis thaliana also showed increased susceptibility to the green peach aphid (Myzus persicae), indicating that the role α-DOX is conserved in other plant-aphid interactions.

scholarly journals Cyclic AMP Restores Appressorium Formation Inhibited by Polyamines in Magnaporthe grisea

1998 ◽  
Vol 88 (1) ◽  
pp. 58-62 ◽  
Author(s):  
Woo-Bong Choi ◽  
Shin-Ho Kang ◽  
Yin-Won Lee ◽  
Yong-Hwan Lee
Keyword(s):  
Cyclic Amp ◽  
Magnaporthe Grisea ◽  
Conidial Germination ◽  
Intracellular Camp ◽  
Elevated Concentration ◽  
Appressorium Formation ◽  
Polyamine Biosynthesis ◽  
Wide Range ◽  
Biosynthesis Inhibitors ◽  
Exogenous Addition

Magnaporthe grisea, the causal agent of rice blast, forms a dome-shaped melanized infection structure, an appressorium, to infect its host. Environmental cues that induce appressorium formation in this fungus include the hydrophobicity and hardness of the contact surface and chemicals produced by the host. An elevated concentration of intracellular cyclic AMP (cAMP) has been implicated in appressorium differentiation in M. grisea. Polyamines (putrescine, spermidine, and sper-mine) are involved in cell growth and differentiation in a wide range of organisms. To understand the role of polyamines in appressorium differentiation in M. grisea, intracellular polyamines were quantified, and the effects of polyamines and polyamine biosynthesis inhibitors on conidial germination and appressorium formation were tested. High levels of polyamines were detected in freshly collected spores, but the levels decreased during conidial germination. Spermidine was found to be the major component. Polyamines and polyamine biosynthesis inhibitors did not affect conidial germination, but polyamines specifically impaired appressorium formation. Furthermore, exogenous addition of cAMP restored appressorium formation inhibited by poly-amines. These results suggest that polyamines may reduce intracellular cAMP levels in M. grisea, leading to the inhibition of appressorium formation.

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