Nipponbare and wild rice species as unexpected tolerance and susceptibility sources against Schizotetranychus oryzae (Acari: Tetranychidae) mite infestation

Abstract

Cultivated rice (Oryza sativa L.) is frequently exposed to multiple stresses, including Schizotetranychus oryzae mite infestation. Rice domestication has narrowed the genetic diversity of the species, reducing the stress resistance and leading to a wide susceptibility. Therefore, wild rice species present an alternative to search for this lost variability. Aiming to observe the response of two wild rice species (Oryza barthii and Oryza glaberrima) and two Oryza sativa genotypes (cv. Nipponbare and O. sativa f. spontanea) to S. oryzae infestation, we used agronomic, physiological and molecular analyses. Surprisingly, analyses of leaf damage, histochemistry, chlorophyll concentration and chlorophyll fluorescence showed that the wild species present higher level of leaf damage, increased accumulation of H 2 O 2 and lower photosynthetic capacity when compared to O. sativa genotypes under infested conditions. Infestation did not affect plant height, but decreased tiller number, except in cv. Nipponbare, whose development was not affected. Infestation also caused the death of wild plants during the reproductive stage, unlike O. sativa genotypes, which were able to tolerate stress and produce seeds. While infestation did not affect the weight of 1,000 grains in both O. sativa genotypes, the number of panicles per plant was affected only in O. sativa f. spontanea, and the percentage of full seeds per panicle and seed length were increased only in cv. Nipponbare. Proteomic analysis allowed us to identify 195 differentially abundant proteins when comparing susceptible (O. barthii) and tolerant (O. sativa cv. Nipponbare) genotypes under control and infested conditions. We found that O. barthii has a less abundant antioxidant arsenal. In addition, it is unable to modulate proteins involved with general metabolism and energy production under infested condition. In Nipponbare we found high abundance of detoxification-related proteins, general metabolic processes and energy production, which allows us to suggest that, under infested condition, the primary metabolism is maintained more active compared to O. barthii. Also, Nipponbare presents a greater abundance of defense-related proteins, such as osmotin, ricin B-like lectin, and protease inhibitors of the Bowman Birk trypsin inhibitor family, as well as higher levels of the compatible osmolyte Proline under infested condition. Identification of these differentially abundant proteins can be used as an important biotechnological tool in breeding programs that aim increased tolerance to phytophagous mite infestation.

The Price of the Induced Defense Against Pests: A Meta-Analysis

“…The term “ fitness” is related with “ reproductive success” and during years the effects of herbivory on plant fitness were measured exclusively in terms of seed production (Strauss, 1997 ). Other parameters related with plant reproduction have also been used as fitness indicators, like seed yield, fruit production or seed size (Bardner, 1968 ; Sances et al, 1982 ; Summers and Newton, 1989 ; Bufon et al, 2020 ). However, the term “ fitness” is more complex and the parameters used to estimate it have been changing along the time.…”

“…As phytophagous feeding causes numerous alterations of the plant primary metabolism, several authors have monitored different parameters related to photosynthesis, transpiration, remobilization of carbon and nitrogen resources, sugar or water content as indicators of plant growth (Sances et al, 1979 ; Hutchison and Campbell, 1994 ; Watanabe and Kitagawa, 2000 ; Nykänen and Koricheva, 2004 ; Botha et al, 2006 ; Giri et al, 2006 ; Schmidt et al, 2009 ; Halitschke et al, 2011 ; Ochoa-Lopez et al, 2015 ; Machado et al, 2017 ; Santamaria et al, 2017 , 2018 ; Bufon et al, 2020 ). In addition, as the leaves are the photosynthetic organs, relative growth rate (RGR), leaf number, leaf length, leaf area, specific leaf area, leaf/mass ratio, biomass or biomass allocation have been measured to evaluate plant growth (Vranjic and Ash, 1997 ; Nykänen and Koricheva, 2004 ; Schmidt et al, 2009 ; Sotelo et al, 2014 ; Ochoa-Lopez et al, 2015 ; Santamaria et al, 2018 ; Bufon et al, 2020 ). Although the most direct measure of fitness is to analyse the offspring of a plant, plant fitness has also been inferred from the study of the plant reproductive structures (flowers), propagules (seeds) or the actual reproductive success (number of germinating seeds) (Erb, 2018 ).…”

Structural, Physiological and Biochemical Alterations on the Galled-Stem of Tamarix nilotica

“…The increased proline content observed in infected Tamarix galls (Table 2) most likely had an adaptive function, because proline has been reported as a universal osmolyte that accumulates in response to several stresses, serves as an energy source, and plays a protective role as a hydroxyl radical scavenger (Mansour & Salama, 2020). Proline accumulation has also been observed in several infested plants (Khattab, 2007;Bufon et al, 2020).…”