Institute for Plant Protection, Croatian Centre for Agriculture, Food and Rural Affairs, Gorice 68b, 10000, Zagreb, Croatia.
Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University & Institute of Experimental Botany ASCR, Šlechtitelů 27, 783 71, Olomouc, Czech Republic.
J Plant Physiol. 2019 Jan;232:107-114. doi: 10.1016/j.jplph.2018.10.027. Epub 2018 Nov 4.
Although structurally simple, viroids can trigger numerous changes in host plants and cause loss of yield in agronomically important crops. This study investigated changes in the endogenous status of phytohormones and antioxidant enzyme activity in Solanum tuberosum cv. Désirée in response to Potato spindle tuber viroid (PSTVd) infection. Phytohormone analysis showed that the content of endogenous jasmonic acid (JA) and its precursor cis-OPDA significantly increased in leaves, while the content of castasterone (CS) increased in both leaves and tubers of systemically infected plants compared to mock-inoculated control plants at 8 weeks post-inoculation. The indole-3-acetic acid content moderately increased only in tubers, while no differences in salicylic acid and abscisic acid content were observed between infected and control plants. Changes in endogenous phytohormone content were associated with upregulated expression of genes involved in the biosynthesis of JA and brassinosteroids, and the metabolism of auxins. Additionally, PSTVd infection provoked overproduction of hydrogen peroxide, which coincided with increased activity of guaiacol peroxidase in leaves and ascorbate peroxidase in potato tubers. The activity of catalase decreased in leaves, while superoxide dismutase activity remained steady regardless of the treatment and organ type. Total ascorbate and glutathione did not change significantly, although a shift towards oxidized forms was observed. Results suggest the existence of organ-specific differences in phytohormone and antioxidative responses in potato upon PSTVd infection. Possible effects of the observed changes on symptom development are discussed.
尽管结构简单，类病毒却能引发宿主植物的诸多变化，并导致重要农作物减产。本研究调查了感染马铃薯纺锤块茎类病毒（PSTVd）后，马铃薯品种‘Désirée’内源植物激素状态和抗氧化酶活性的变化。植物激素分析表明，接种后 8 周，感病植株叶片中内源茉莉酸（JA）及其前体顺式-OPDA 的含量显著增加，而系统感染植株叶片和块茎中甾醇的含量均高于Mock 接种对照植株。吲哚-3-乙酸（IAA）含量仅在块茎中适度增加，而感染植株与对照植株之间水杨酸和脱落酸含量无差异。内源植物激素含量的变化与 JA 和油菜素内酯生物合成以及生长素代谢相关基因的上调表达有关。此外，PSTVd 感染会引发过氧化氢的过度产生，这与叶片中愈创木酚过氧化物酶和马铃薯块茎中抗坏血酸过氧化物酶活性的增加相一致。叶片中的过氧化氢酶活性降低，而超氧化物歧化酶活性无论处理和器官类型如何均保持稳定。虽然观察到氧化形式的转变，但总抗坏血酸和谷胱甘肽含量没有明显变化。结果表明，马铃薯感染 PSTVd 后，植物激素和抗氧化反应存在器官特异性差异。讨论了观察到的变化对症状发展的可能影响。
