Physiological Responses of Apple Rootstock M.9 to Infection by Fusarium solani

Abstract

Apple replant disease (ARD) causes enormous economic loss and threatens the survival of apple industry worldwide. Fusarium solani is one of the pathogens that has been proven to cause ARD. Samples were collected at different time periods to investigate the mechanism of defense responses of apple to F. solani infection by monitoring the biomass, reactive oxygen species (ROS), and antioxidant enzyme activities of the apple rootstock ‘M.9T337’. In addition, the abundance of transcription of four pathogenesis-related (PR) proteins involved in antifungal defense was monitored. The results showed that the apple root system was normal and had small brown areas. However, there is a rapid burst of ROS during the early infection stage, and the activities of antioxidant enzymes and transcription of PRs increased during this period. With the extension in infection time, the infected root tissues displayed dark brown necrosis, and the activities of antioxidant enzymes and abundance of transcription of PRs decreased gradually after reaching their peak. Eventually, the plant biomass decreased, and the plant died. In conclusion, the levels of ROS and activities of antioxidant enzymes played an active role during the early stage of resistance of ‘M.9T337’ apples to infection by F. solani. Infection by F. solani can destroy the ROS scavenging system, causing oxidative damage and inhibiting the growth of apple rootstocks.

Toward a holistic view of orchard ecosystem dynamics: A comprehensive review of the multiple factors governing development or suppression of apple replant disease

“…In fact, the claim that Fusarium spp. are key pathogens associated with ARD in other regions of the world is a recurring inaccurate statement reported in many of these studies ( Wang et al, 2018a ; Xiang et al, 2021b ; Liu et al, 2022 ). The statement regarding Fusarium functioning as an ARD pathogen is primarily based upon sequence-based studies in which relative abundances of Fusarium spp.…”

“…Thus far however, the evidence in support of the role of Fusarium as an ARD-causing agent in China remains inconclusive. That said, limited support for this claim was recently provided in a study in which a single isolate of F. solani (originally isolated from apple roots growing in replant soil from the Bohai Bay region) was shown to significantly reduce plant growth of tissue cultured M.9 rootstocks relative to non-infected control plants after 1 month (1 × 10 3 spores per ml of soil; Xiang et al, 2021b ). Multiple isolates of F. solani recovered from apple in the Western Cape province of South Africa ( Tewoldemedhin et al, 2011b ) or Washington State United states ( Mazzola, 1998 ) were found to be non-pathogenic toward apple.…”

Involvement of MdWRKY40 in the defense of mycorrhizal apple against fusarium solani

“…F. solani (MG836251.1) is one of the pathogens that has been proven to cause ARD [ 13 ]. Infection with F. solani depressed the photosystem performance of apple seedling leaves, destroyed the ROS scavenging system, caused oxidative damage, and increased the number of black and brown necrotic spots on apple roots [ 10 , 14 ]. Those series of physiologic and biochemical reactions can lead to severe root tip necrosis and decay until plant death occurs several days or weeks after F. solani infection [ 15 ].…”

Allium fistulosum L. Alleviates Apple Replant Disease by Suppressing Fusarium solani

“…There are many factors that cause ARD, and most of the evidence indicates that the disease is primarily caused by biotic factors [ 1 ]. Numerous biological agents have been implicated as causes of ARD, including pathogenic nematodes [ 3 , 10 ], fungi [ 2 , 6 , 8 , 11 ] and bacteria [ 12 ]. The recent studies have suggested that pathogenic fungi such as Phytophthora , Pythium , Cylindrocarpon , and Rhizoctonia are associated with ARD [ 13 , 14 ].…”

“…Fusarium can infect specific parts of many plants causing various plant diseases [ 21 ]. Approximately half of the 40 species in the genus parasitize plants and cause root rots, vascular wilts, and storage rots [ 11 , 22 ]. The Fusarium solani species complex (FSSC) can also infect different host plants, causing necrosis of the plant tissues as well as varying degrees of wilting [ 23 ].…”