Onion plants (Allium cepa L.) react differently to salinity levels according to the regulation of aquaporinsKey Message
Alireza Solouki,
Jose Ángel Berna-Sicilia,
Alberto Martinez-Alonso,
Nidia Ortiz-Delvasto,
Gloria Bárzana,
Micaela Carvajal
Affiliations
Alireza Solouki
Department of Horticulture, College of Aburaihan, University of Tehran, Tehran, Iran
Jose Ángel Berna-Sicilia
Aquaporins Group. Plant Nutrition Department, Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Campus Universitario de Espinardo, Edificio 25, 30100 Murcia, Spain
Alberto Martinez-Alonso
Aquaporins Group. Plant Nutrition Department, Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Campus Universitario de Espinardo, Edificio 25, 30100 Murcia, Spain
Nidia Ortiz-Delvasto
Aquaporins Group. Plant Nutrition Department, Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Campus Universitario de Espinardo, Edificio 25, 30100 Murcia, Spain
Gloria Bárzana
Aquaporins Group. Plant Nutrition Department, Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Campus Universitario de Espinardo, Edificio 25, 30100 Murcia, Spain; Corresponding author.
Micaela Carvajal
Aquaporins Group. Plant Nutrition Department, Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Campus Universitario de Espinardo, Edificio 25, 30100 Murcia, Spain; Corresponding author.
As salinity is one of the main environmental stresses that reduces the growth and productivity of crops by reducing water uptake and transport, in this work, we associated the physiological tolerance response of onion to increased NaCl concentration (from 25, 50, 75, to 100 mM) with the expression of aquaporins. Measurements of transpiration, gas exchange and nutrients content in leaf, roots and bulb tissues were determined in relation to the expression of PIP2, PIP1, and TIP2 aquaporin genes. The results indicated a significant decrease in growth in leaves, roots and bulbs only when 50 mM NaCl was applied. However, this was not correlated with the rest of the parameters, such as transpiration, number of stomata, osmotic potential, or chlorophyll concentration. In this way, the finding that the decreases in Mn, Zn and B observed in leaves, roots and bulbs at 50 mM NaCl were related to the expression of aquaporins, leaded to propose two phases of responses to salinity depending on level of NaCl. Therefore, the activation of PIP2 at 75 mM, in relation to Zn uptake, is proposed as relevant in the response of onion to high salinity.
