Capsicum annuumTobacco Mosaic Virus-Induced Clone 1 Expression Perturbation Alters the Plant's Response to Ethylene and Interferes with the Redox Homeostasis

Abstract

Capsicum annuum tobacco mosaic virus (TMV)-induced clone 1 (CaTin1) gene was expressed early during incompatible interaction of hot pepper (Caspsicum annuum) plants with TMV and Xanthomonas campestris. RNA-blot analysis showed that CaTin1 gene was expressed only in roots in untreated plants and induced mainly in leaf in response to ethylene, NaCl, and methyl viologen but not by salicylic acid and methyl jasmonate. The ethylene dependence of CaTin1 induction upon TMV inoculation was demonstrated by the decrease of CaTin1 expression in response to several inhibitors of ethylene biosynthesis or its action. Transgenic tobacco (Nicotiana tabacum) plants expressing CaTin1 gene in sense-or antisense-orientation showed interesting characteristics such as the accelerated growth and the enhanced resistance to biotic as well as abiotic stresses. Such characteristics appear to be caused by the elevated level of ethylene and H 2 O 2 . Moreover, in transgenic plants expressing antisense CaTin1 gene, the expression of some pathogenesis-related genes was enhanced constitutively, which may be mainly due to the increased ethylene level. The promoter of CaTin1 has four GCC-boxes, two AT-rich regions, and an elicitor-inducible W-box. The induction of the promoter activity by ethylene depends on GCC-boxes and by TMV on W-box. Taken together, we propose that the CaTin1 up-regulation or down-regulation interferes with the redox balance of plants leading to the altered response to ethylene and biotic as well as abiotic stresses.Multiple preformed antimicrobial compounds contribute to the constitutive defense machinery of plants against pathogenic organisms. In addition, plants can trigger the inducible defense programs upon the perception of invaders. The early signaling molecules leading to R-gene-mediated resistance are ion fluxes, GTP-binding proteins, protein kinases, phosphatases, and phospholipases (Hammond-Kosack and Jones, 1996). Plants also respond to external stimuli such as microbial elicitors of cell death and/or defense responses by changing the calcium influx of the cell (Ebel and Scheel, 1997;Higgins et al., 1998). The increase of cytosolic calcium leads to cell death, which seems necessary for hypersensitive cell death triggered by rust fungi (Xu and Heath, 1998). The calcium channel blocker La 31 , on the other hand, prevents the bacteriainduced hypersensitive response (HR) in soybean (Glycine max) leaves (Levine et al., 1996). The burst in the oxidative metabolism generated within minutes of infection leads to the accumulation of the reactive oxygen intermediates (ROI) such as H 2 O 2 and superoxide anion (O 2 d 2 ), involving NADPH-dependent oxidase. ROI serve as signaling molecules, for example in the recognition of the attack by fungal pathogens (Lamb and Dixon, 1997).Ethylene is widely known to modulate the organ senescence induced by various stress factors such as plant pathogens (Moore et al., 2000), O 3 2 (Pell et al., 1997), and hypoxia (He et al., 1996). O 3 2 induces genes involved in the ethylene biosynthes...

The Nodule-Specific PLAT Domain Protein NPD1 Is Required for Nitrogen-Fixing Symbiosis

“…The Medicago PLAT-plant-stress proteins (MtPLAT5, MtPLAT6, MtPLAT7, and MtPLAT8) belong to a subgroup that includes the Arabidopsis (Arabidopsis thaliana) PLAT-domain proteins AtPLAT1, AtPLAT2, and AtPLAT3 (Hyun et al, 2014). Other known PLAT-domain proteins included in the tree are the Capsicum annuum tobacco mosaic virus-induced clone 1 (Shin et al, 2004) and C. annuum pathogeninduced protein 2 (Lee et al, 2006).…”

Causes and consequences of plant-associated biofilms

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Nodule‐specific PLAT domain proteins are expanded in the Medicago lineage and required for nodulation

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