Involvement of PHYB in resistance to Cucumber mosaic virus in Nicotiana tabacum

Abstract

Plants are exposed to a diversity of environmental stresses throughout their life cycles and need to constantly regulate their developmental and physiological processes to respond various external stimuli. It is well known that the interaction between light and plant defence is multifaceted and complicated. Here, the recombinant vector pRNAi-LIC-PHYB was used for achieving tobacco (Nicotiana tabacum) PHYB defective mutant via the Agrobacterium-mediated transformation method. Furthermore, we investigated molecular and physiological principles in PHYB defective N. tabacum plants in response to Cucumber mottle virus (CMV) infection. Our results indicated that PHYB defective plants were more susceptible to CMV infection. There were higher viral replication level, more impetuous viral symptoms and more serious stress damages in PHYB defective mutants along the time going when compared with wild-type (wt) plants. Moreover, the transcripts of defence-related genes and activities of antioxidant enzymes in phyB mutants were down-regulated when compared with wt plants after CMV infection. Overall, our results provided new information about the molecular link between PHYB and plant immune system in N. tabacum.

Positive role of phytochromes in Nicotiana tabacum against Cucumber mosaic virus via a salicylic acid‐dependent pathway

“…In this paper, a study was conducted to investigate the role of phytochromes in the interaction between N. tabacum and CMV. The results indicate that phytochromes phyA and phyB play a crucial role in the development of the defence ability in N. tabacum induced by CMV, which is somewhat consistent with previous suggestions that phytochromes are essential for plants to induce complete defence responses against attacks from various pathogens (Jeong et al ., ; Kazan & Manners, ; Xie et al ., ; Li et al ., ). Based on the results from tobacco phytochrome mutants, it is also hypothesized that a heightened sensitivity to CMV in phyA or phyB mutants might occur by repressing the SA‐mediated defence pathway in N. tabacum .…”

“…In addition, studies have shown that phytochromes also act as key mediators of a plethora of diverse biotic and abiotic stresses (Carvalho et al ., ). Previous studies have suggested that phyB is essential for the defence strategies of N. tabacum against CMV (Li et al ., ). The results of the present study show that mutation of phyA also compromises the resistance ability of N. tabacum induced to CMV attack.…”

“…Construction of RNAi vector, plant transformation, regeneration, selection and identification were similar to the methods described by Li et al . (). The primer sequences used in vector construction are shown in Table .…”

“…In view of the importance of phytochromes in plant responses to pathogens, understanding the influence of phytochromes on the interaction between plants and pathogens has an important reference value for the design of new management strategies for plant disease control. Previous studies have suggested that phyB is essential for the defence strategies of N. tabacum against CMV (Li et al, 2015). It is anticipated that phyA would also participate in CMV-induced defence responses.…”

Comparative transcriptome profiling of Arabidopsis Col-0 in responses to heat stress under different light conditions

“…The phytochrome (phy) family of receptors played a major role in perceiving red (R) (Rangani et al 2015) and far-red (FR) light (Li et al 2015), which carried information on the availability of photosynthetic energy and the proximity of neighboring plants (Chen and Chory 2011). Therefore, they were essential for the regulation of developmental processes from seed germination to the timing of reproductive development (Franklin and Quail 2010).…”