2023/01/05 by Hassan Yusuf Sulaiman, Eve Runno-Paurson, Eve Kaurilind +1 · 1 citation
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Horticultural and Viticultural Research #Plant Parasitism and Resistance #Yeasts and Rust Fungi Studies
paper · pdf · doi:10.1093/jxb/erad001
openalex publication_date 2023/01/05 · openalex created_date 2023/01/08 · openalex updated_date 2026/08/01
Rust infection results in decreases in photosynthesis and stress volatile emissions, but how these changes vary among host species has not been studied. We demonstrated that the impact of the obligate biotrophic fungus, Puccinia coronata f. sp. avenae, on foliage physiological processes is stronger in the primary host, Avena sativa (cultivated oat), than in the alternate host, Rhamnus frangula (alder buckthorn). Photosynthesis decreased with increasing percentage of damaged leaf area (DA) in both species, but reductions were greater in A. sativa. In A. sativa, photosynthetic reductions resulted from reductions in stomatal conductance and photosynthetic capacity; in R. frangula, reductions were due to reduced capacity. Infection reduced photosynthetic biomass and key nutrients in A. sativa, but not in R. frangula. In A. sativa, stress-elicited emissions (methyl jasmonate, green leaf volatiles, long-chain saturated aldehydes, mono- and sesquiterpenes, benzenoids, and carotenoid breakdown products) increased with increasing DA from 0% to 40%, but decreased with further increases in DA. In R. frangula, volatile emissions were slightly elicited but, surprisingly, constitutive isoprene emissions were enhanced. Different hosts had characteristic volatile fingerprints, indicating differential activation of biochemical pathways. Fungal-elicited reductions in photosynthesis scale uniformly with stress severity. In the sensitive host, biphasic scaling of volatiles indicates that heavy spread of chlorosis/necrosis leads to an overall cessation of physiological functioning.