Combined effects of excess boron and salinity on root histology of Zea mays L. amylacea from the Lluta Valley (Arica, Chile)

Abstract

Cell structure and alterations in tissue organization were analyzed for roots of Zea mays L. amylacea as a consequence of high salinity and boron (B) levels. Saline treatment concentrations were 100 mM NaCl (Low salinity, L) and 430 mM NaCl (High salinity, H). An excess of B was supplied as boric acid to obtain 20 (334 µM) and 40 (668 µM) mg B kg -1 in the nutrient solution for 20 days. Our results complement other studies on the amylacea ecotype and confirm the high degree of tolerance to salinity and excess B shown by this variety. The application of B under no salt and low salinity conditions did not result in structure changes in root cortex cells nor the vascular cylinder. Under high salinity conditions amylacea root cells showed slight alterations, such as an increase in the number of rows of cells. These high salinity conditions did not result in thickness of the stele.Key words: Amylacea, boron, histological, root, salinity. RESUMEN La estructura celular y las alteraciones en la organización del tejido de raíz se analizaron en Zea mays L. amylacea como consecuencia de altos niveles de boro (B) y de salinidad. Concentraciones de los tratamientos de salinidad fueron 100 mM NaCl (baja salinidad, L) y 430 mM NaCl (alta salinidad, H). El exceso de B se suministró como ácido bórico para obtener 20 (334 µM) y 40 (668 µM) B mg kg -

The effect of biochar on the physiological, morphological and anatomical characteristics of mung bean roots after exposure to salt stress

“…Salinity diminishes root diameter and length [9], affects expansion processes and cell division [10,11], and reduces the size of apical meristems, the VC and cortex. Furthermore, exodermis and endodermis suberization processes are expedited by salt stress [12,13]. The main anatomical response to salinity is cell-wall alteration.…”

Interactive effects of excess boron and salinity on response curves of gas exchange to increase in the intensity of light of Zea mays amylacea from the Lluta Valley (Arica-Chile)

“…This the case in the Lluta valley of northern Chile, where elevated levels of B in soils and irrigation water limit local agricultural production to a few landrace crops of this region, which has less than 1 mm annual precipitation (Bastías et al, 2004b). Zea mays L. amylacea is a sweet maize variety well adapted to the agro-ecological characteristics of the Lluta Valley; the physiological mechanisms of tolerance to high levels of NaCl and B in amylacea maize have been studied previously with respect to the salt accumulation capacity of tissues, photosynthetic assimilation and water relations (Bastías et al, 2004b), as well as root hydraulic conductance (Lo), abundance of aquaporins and ATPase activity (Bastías et al 2004a, Martínez-Ballesta et al, 2008. Additionally, other studies at the leaf and root levels have been published (Bastias et al, 2013a, Bastias et al, 2013b showing the degree of tolerance to salinity and excess B.…”