Biochemical changes in cultivars of sweet oranges infected with citrus tristeza virus

Abstract

Citrus fruit production occupies a place of considerable importance in the economy of the world including Pakistan. Tristeza disease caused by Citrus Tristeza Virus (CTV) exists in various forms that may or may not cause symptoms in the plants. The bioactive compounds and antioxidants are naturally present in plants and provide a defense mechanism that is generally accelerated in response to a stress. The objective of the present study was to target and analyze the citrus plants that were CTV positive to observe the changes in the enzymatic and non-enzymatic antioxidants of citrus (Sweet Oranges only). It was observed that in response to CTV infection, both the non-enzymatic antioxidants (total flavonoid, ascorbic acid, phenolic acid) and enzymatic antioxidants (catalase, superoxide dismutase and peroxidase) activities showed an increasing trend overall. The profiling of antioxidants in response to a viral infection may help in the discovery of new biomarkers that can be used as a monitoring tool in disease management.

The comprehensive changes in soil properties are continuous cropping obstacles associated with American ginseng (Panax quinquefolius) cultivation

“…Phenolic acids are produced by plants under external stress [37][38][39][40] . They do have many beneficial functions, such as antibacterial, antioxidant and so on, which can alleviate the stress of plants 41 . However, with the increase of phenolic acid secretion, some phenolic acids will penetrate into the soil and affect the soil microorganisms.…”

Viruses Infecting Trees and Herbs That Produce Edible Fleshy Fruits with a Prominent Value in the Global Market: An Evolutionary Perspective

“…The infected plant can exhibit a variety of symptoms, highly characteristic ones being the induction of colorful patterns (mosaic, chlorosis, necrosis, local necrotic, or chlorotic spots) and distortions (twisting, curling) on leaves, as well as malformation on the branches and discoloration and streaks on the flower petals [60]. In addition, viruses can affect the size, shape, and quality of the fruit, displaying visible symptoms on the fruit such as ringspots, pits, mottling, or line patterns that diminish its appearance and/or organoleptic properties [116]. It is worth mentioning, however, that even though the same virus can infect different plant species, the symptomatology and severity will not be the same [117][118][119][120][121][122][123][124].…”

“…Proteins such as superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (GPX), and ascorbate peroxidase (APX) were found at high levels, suggesting that CTV induces increased oxidative stress. In addition to SOD, CAT, GPX, and APX, accumulation of amino acids, ascorbate, vitamin E, and phenolic compounds has been found and may contribute to preventing cell death due to oxidative stress caused by CTV [116,160].…”

“…The world production of citrus fruits was estimated at 138 million tons in 2019, with a production value of USD 47.7 billion. The main countries with citrus-producing areas are China, France, United States, Spain, and Chile [45,116]. The major problem in the production of citrus fruits is CTV, which infects plants of the Rutaceae family but mainly the genus Citrus (Figure 4B; Supplementary Table S4) [159].…”

Resistance Assessment of Citrus Varieties against Gummosis Disease caused by Phytophthora nicotianae under Natural Field Conditions

“…The and increased production of secondary metabolites such as flavonoids enhance the response against pathogens in citrus cultivars thus make them resistant (Munir et al, 2019).…”