Potassium phosphite increases tolerance to UV-B in potato

Abstract

The use of biocompatible chemical compounds that enhance plant disease resistance through Induced Resistance (IR) is an innovative strategy to improve the yield and quality of crops. Phosphites (Phi), inorganic salts of phosphorous acid, are environment friendly, and have been described to induce disease control. Phi, similar to other plant inductors, are thought to be effective against different types of biotic and abiotic stress, and it is assumed that the underlying signaling pathways probably overlap and interact. The signaling pathways triggered by UV-B radiation, for instance, are known to crosstalk with other signaling routes that respond that biotic stress. In the present work, the effect of potassium phosphite (KPhi) pre-treatment on UV-B stress tolerance was evaluated in potato leaves. Plants were treated with KPhi and, after 3 days, exposed to 2 h/day of UV-B (1.5 Watt m(-2)) for 0, 3 and 6 days. KPhi pre-treatment had a beneficial effect on two photosynthetic parameters, specifically chlorophyll content and expression of the psbA gene. Oxidative stress caused by UV-B was also prevented by KPhi. A decrease in the accumulation of hydrogen peroxide (H2O2) in leaves and an increase in guaiacol peroxidase (POD) and superoxide dismutase (SOD) activities were also observed. In addition, the expression levels of a gene involved in flavonoid synthesis increased in UV-B-stressed plants only when pre-treated with KPhi. Finally, accumulation of glucanases and chitinases was induced by UV-B stress and markedly potentiated by KPhi pre-treatment. Altogether, this is the first report that shows a contribution of KPhi in UV-B stress tolerance in potato plants.

Los fosfitos como alternativa para el manejo de problemas fitopatológicos

“…Los fosfitos, como alternativa para el control de organismos fitoparásitos, han sido estudiados ampliamente y su eficacia se ha probado contra protozoarios, oomycetes, hongos, bacterias y nematodos fitoparásitos (Cuadro 1); adicionalmente, se ha comprobado su eficacia como bioestimulador (Gómez-Merino y Trejo-Téllez, 2015), para disminuir los daños por malezas (Manna et al, 2016;Achary et al, 2017) y radiación UV-B (Oyarburo et al, 2015).…”

“…However, 40 years later, phosphites returned to the agrochemicals market as an alternative for controlling plant diseases, when the French company Rhône-Poulenc offered the active ingredient fosetyl-aluminum to control mildews and diseases caused the Phytophthora genus (Tkaczyk et al, 2016;Achary et al, 2017). Phosphites, as an alternative for controlling phytoparasite organisms, have been extensively studied and proven to be effective against protozoa, oomycetes, fungi, bacteria and phytoparasite nematodes (Table 1), as well as biostimulators (Gómez-Merino and TrejoTéllez, 2015) that reduce damages caused by weeds (Manna et al, 2016;Achary et al, 2017) and UV-B radiation (Oyarburo et al, 2015).…”

Early potato production is positively affected by potassium fertilization

“…Bishwoyog and Swarnima (2016) reviewed that a yield of 30 tons of potato tubers will removes 250 kg of potassium per hector. It has been established in several previous studies that addition of potassium at adequate level, which depends on soil fertility, crop rotation and soil type, improves tuber yield attributes (Zelelew et al, 2016;Haddad et al, 2016), tuber quality attributes (Abd El-Latif et al, 2011;Michalska et al, 2016), plant tolerance to biotic and abiotic stresses (Abd El-Latif et al, 2011;Oyarburo et al, 2015;Liljeroth et al, 2016).…”

Plant and microbe genomics and beyond: potential for developing a novel molecular plant nutrition approach

“…Interestingly, Estrada-Ortiz et al (2013) showed that adding Phi to the nutrient solution used for growing strawberries improves some fruit quality characteristics when there is sufficient Pi, and it has been postulated that Phi could activate defense mechanisms against pathogen attack. In fact, Oyarburo et al (2015) recommend the use of Phi as an agent to activate defense, cellular signal transduction and quality improvement mechanisms in certain conditions and for certain crops. The only way that plants can use Phi as a P-source is through the expression of a bacterial phosphite dehydrogenase, as has been reported for Arabidopsis thaliana and Nicotiana tabacum (López-Arredondo and Herrera-Estrella 2012), which opens up new opportunities to use Phi as a P-source in P nutrition approaches.…”