Root-System Architectures of Two Cuban Rice Cultivars with Salt Stress at Early Development Stages

Abstract

Soil salinity is a critical problem for rice production and is also often associated with phosphors (P) deficiency. Plant hormones, like brassinosteroids, were shown to play a role in plant responses to different stresses and are also expected to mitigate salt stress. The aim of this study was to compare shoot growth and root architecture traits of two rice cultivars (INCA LP-5 and Perla de Cuba) during early plant development in response to salt, P limitation and a brassinosteroid. Seeds were placed in (I) paper rolls for 7 days and (II) mini-rhizotrons for 21 days without or with salt (50 mM NaCl), without or with 24-epibrassinolide (10−6 M) pre-treatment, and with two levels of P (10 or 1 ppm). The root system of LP-5 was larger in size and extent, while the roots of Perla were growing denser. Salt affected mainly the size- and extent-related root characteristics and explained about 70% of the variance. The effect of P was more pronounced without salt treatment. In Perla, P supply reduced the salt effect on root growth. The brassinosteroid had hardly any effect on the development of the plants in both experiments. Due to the high dependence on experimental factors, root length and related traits can be recommended for selecting young rice cultivars regarding salt stress and P deprivation.

Physiological Responses to Salt Stress at the Seedling Stage in Wild (Oryza rufipogon Griff.) and Cultivated (Oryza sativa L.) Rice

“…Indeed, despite a common similar reduction in the maximum shoot length (Figure 1B), the extension of root system (i.e., total length, volume and surface area) was kept constant in B, while it was reduced in the genotypes with longer roots (Table 1). A similar reduction in root network length was reported in different O. sativa cultivars under salt stress at the seedling stage, especially in bigger ones [40], and it was linked to suppression of cell division and elongation [41]. Development of lateral roots producing higher root branching can influence root hydraulic conductivity and water supply [42]; thus, it can be an important trait for plants growing under salt stress.…”

Salinity Tolerance Evaluation of Rice (Oryza sativa L.) ‘Tubtim Chumphae’ Seedling and Early Vegetative Stage

“…Roots were fully grown in the treatment without salt stress but growth decreased when NaCl concentration increased 35 . Similar results were also recorded in shoots and roots of Cuban and Thai rice landraces 36,37 . The HCA heatmap also revealed similar results, with decreasing growth parameters at higher salt stress levels (Fig.…”

Contribution of Arbuscular Mycorrhizal Fungi (AMF) in Improving the Growth and Yield Performances of Flax (Linum usitatissimum L.) to Salinity Stress

“…In particular, the application of AMF increased the root-to-shoot ratio in inoculated plants, revealing that AMF-inoculated plants diverted more biomass to the roots than to the shoots. An increased root-to-shoot ratio is generally thought to enhance the source-to-sink ratio for water and nutrients and could, therefore, prove advantageous under salinity conditions [60,61].…”