Expression and functional analyses of the plastid lipid-associated protein CHRC suggest its role in chromoplastogenesis and stress.
نویسندگان
چکیده
Chromoplastogenesis during flower development and fruit ripening involves the dramatic overaccumulation of carotenoids sequestered into structures containing lipids and proteins called plastid lipid-associated proteins (PAPs). CHRC, a cucumber (Cucumis sativus) PAP, has been suggested to be transcriptionally activated in carotenoid-accumulating flowers by gibberellin (GA). Mybys, a MYB-like trans-activator identified here, may represent a chromoplastogenesis-related factor: Its expression is flower specific and parallels that of ChrC during flower development; moreover, as revealed by stable ectopic and transient-expression assays, it specifically trans-activates ChrC promoter in flowers accumulating carotenoids and flavonoids. A detailed dissection of ChrC promoter revealed a GA-responsive element, gacCTCcaa, the mutation of which abolished ChrC activation by GA. This cis-element is different from the GARE motif and is involved in ChrC activation probably via negative regulation, similar to other GA-responsive systems. The GA responsiveness and MYBYS floral activation of the ChrC promoter do not overlap with respect to cis-elements. To study the functionality of CHRC, which is activated in vegetative tissues similar to other PAPs by various biotic and abiotic stresses, we employed a tomato (Lycopersicon esculentum) plant system and generated RNAi-transgenic lines with suppressed LeCHRC. Transgenic flowers accumulated approximately 30% less carotenoids per unit protein than controls, indicating an interrelationship between PAPs and flower-specific carotenoid accumulation in chromoplasts. Moreover, the transgenic LeCHRC-suppressed plants were significantly more susceptible to Botrytis cinerea infection, suggesting CHRC's involvement in plant protection under stress conditions and supporting the general, evolutionarily preserved role of PAPs.
منابع مشابه
Spironolactone Inhibits NADPH Oxidase-Mediated Oxidative Stress and Dysregulation of the Endothelial NO Synthase in Human Endothelial Cells
Accumulating evidence indicates that aldosterone plays a critical role in the mediation of oxidative stress and vascular damage. NADPH oxidase has been recognized as a major source of oxidative stress in vasculature. However, the relation between NADPH oxidase in aldosterone-mediated oxidative stress in endothelial cells remains to be ascertained. The present study aimed to investigate the rel...
متن کاملSpironolactone Inhibits NADPH Oxidase-Mediated Oxidative Stress and Dysregulation of the Endothelial NO Synthase in Human Endothelial Cells
Accumulating evidence indicates that aldosterone plays a critical role in the mediation of oxidative stress and vascular damage. NADPH oxidase has been recognized as a major source of oxidative stress in vasculature. However, the relation between NADPH oxidase in aldosterone-mediated oxidative stress in endothelial cells remains to be ascertained. The present study aimed to investigate the rel...
متن کاملThe Expression of Signal Regulatory Protein-alpha in Normal and Osteoarthritic Human Articular Cartilage and Its Involvement in Chondrocyte Mechano-transduction Response
Signal regulatory proteins (SIRP) belong to immunoglobulin super family (IgSF) and relate to integrin signaling cascades. It has been shown that SIRPa is expressed in a variety of cells including myeloid cells and neurons. In the present study the expression of this IgSF member in articular chondrocytes was investigated. Methods: Using a panel of anti-SIRPalpha antibodies, immunohistochemistry...
متن کاملPlastid Proteomic Analysis in Tomato Fruit Development
To better understand the mechanism of plastid differentiation from chloroplast to chromoplast, we examined proteome and plastid changes over four distinct developmental stages of 'Micro-Tom' fruit. Additionally, to discover more about the relationship between fruit color and plastid differentiation, we also analyzed and compared 'Micro-Tom' results with those from two other varieties, 'Black' a...
متن کاملVulnerability of Prepubertal Mice Testis to Iron Induced Oxidative Dysfunctions In Vivo and Functional Implications
Background The present study describes the susceptibility of prepubertal testis of mice to prooxidant induced oxidative impairments both under in vitro and in vivo exposure conditions. MaterialsAndMethods Following in vitro exposure to iron (5,10 and 25 M), oxidative response measured in terms of lipid peroxidation and hydroperoxide levels in testis of pre pubertal mice (4 wk) was more robust c...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Plant physiology
دوره 142 1 شماره
صفحات -
تاریخ انتشار 2006