Abstract
The F-box protein family is characterized by an F-box motif that has been shown to play an important role in regulating various developmental processes and stress responses. In this study, a novel F-box-containing gene was isolated from leaves of pepper cultivar P70 (Capsicum annuum L.) and designated CaF-box. The full-length cDNA is 2088 bp and contains an open reading frame of 1914 bp encoding a putative polypeptide of 638 amino acids with a mass of 67.8 kDa. CaF-box was expressed predominantly in stems and seeds, and the transcript was markedly upregulated in response to cold stress, abscisic acid (ABA) and salicylic acid (SA) treatment, and downregulated under osmotic and heavy metal stress. CaF-box expression was dramatically affected by salt stress, and was rapidly increased for the first hour, then sharply decreased thereafter. In order to further assess the role of CaF-box in the defense response to abiotic stress, a loss-of-function experiment in pepper plants was performed using a virus-induced gene silencing (VIGS) technique. Measurement of thiobarbituric acid reactive substances (TBARS) and electrolyte leakage revealed stronger lipid peroxidation and cell death in the CaF-box-silenced plants than in control plants, suggesting CaF-box plays an important role in regulating the defense response to abiotic stress resistance in pepper plants.
Highlights
The development and functioning of an organism requires exquisite coordination of the cellular responses to internal and external signals
In order to further confirm the influence of silencing of CaF-box in the cold stress defense response, the thiobarbituric acid reactive substances (TBARS) and electrical conductivity measurements in pepper leaves was tested in the control plant and CaF-box silenced plant
The resulting PCR product was cloned into vector pMD19T (Takara, Dalian, China), the resultant construct was digested with Xba I and BamH I, and the CaF-box fragment was inserted into the Xba I-BamH I site of pTRV2 to form pTRV2-CaF-box
Summary
The development and functioning of an organism requires exquisite coordination of the cellular responses to internal and external signals. Several F-box genes have been characterized which regulate crucially important and diverse physiological processes, such as hormonal response, embryogenesis, seed germination, seedling development, floral organogenesis, lateral root formation, leaf senescence, pathogen resistance, and abiotic stress responses [11,12,13]. (2011) reported that overexpression of the rice F-box protein MAIF1 reduced abiotic stress tolerance and promoted root growth, and a negative role in response to abiotic stress was suggested, possibly through regulating root growth [23]. To investigate possible roles in the defense response against abiotic stresses (cold, salt, osmotic, and heavy metal stress), as well as in plant hormone signaling (abscisic acid and salicylic acid), the expression of CaF-box was analyzed using Real-Time quantitative RT-PCR. The results suggested that CaF-box is a potentially important player in the regulation of plant defense responses
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call