Enhancing quinoa (Chenopodium quinoa) growth in saline environments through salt-tolerant rhizobacteria from halophyte biotope.

The use of plant growth-promoting rhizobacteria (PGPR) in agriculture is one of the most promising approaches to improve plants' growth under salt stress and to support sustainable agriculture under climate change. In this context, our goal was to grow and enhance quinoa growth using native rhizobacteria that can withstand salt stress. To achieve this objective, we isolated rhizobacteria from three saline localities in a semi-arid region in Tunisia, which are characterized by different halophyte species and tested their plant growth-promoting (PGP) activities.

Silicon (Si) mitigates the negative effects of iron deficiency in common bean (Phaseolus vulgaris L.) by improving photosystem activities and nutritional status.

Silicon (Si) is the second most abundant element in the Earth's crust after oxygen. Its beneficial impact on crop development and yield, particularly under stressful conditions such as iron (Fe) deficiency, has been well documented. Fe deficiency is a critical constraint that limits crop production globally.

Changes in organic compounds secreted by roots in two Poaceae species (Hordeum vulgare and Polypogon monspenliensis) subjected to iron deficiency.

Despite their economic and ecological interests, Poaceae are affected by the low availability of iron in calcareous soils. Several studies focused on the capacity of this family to secrete phytosiderophores and organic acids as a mechanism of tolerance to iron deficiency. This work aimed at studying the physiological responses of two Poaceae species; Hordeum vulgare (cultivated barley) and Polypogon monspenliensis (spontaneous species) to iron deficiency, and evaluate especially the release of phytosiderophores and organic acids.

Natural Variation in Physiological Responses of Tunisian Under Iron Deficiency.

Iron (Fe) is an essential element for plant growth and development. The cultivation of leguminous plants has generated strong interest because of their growth even on poor soils. Calcareous and saline soils with poor mineral availability are wide-spread in Tunisia.

The role of nodules in the tolerance of common bean to iron deficiency.

Iron is vital for the establishment and function of symbiotic root nodules of legumes. Although abundant in the environment, Fe is often a limiting nutrient for plant growth due to its low solubility and availability in some soils. We have studied the mechanism of iron uptake in the root nodules of common bean to evaluate the role of nodules in physiological responses to iron deficiency.

Immunolocalization of H(+)-ATPase and IRT1 enzymes in N(2)-fixing common bean nodules subjected to iron deficiency.

The demand for iron in leguminous plants increases during symbiosis, as the metal is utilised for the synthesis of various Fe-containing proteins in both plant and bacteroids. However, the acquisition of this micronutrient is problematic due to its low bioavailability at physiological pH under aerobic conditions. Induction of root Fe(III)-reductase activity is necessary for Fe uptake and can be coupled to the rhizosphere acidification capacity linked to the H(+)-ATPase activity.

Metabolic changes of iron uptake in N(2)-fixing common bean nodules during iron deficiency.

Iron is an important nutrient in N(2)-fixing legume nodules. The demand for this micronutrient increases during the symbiosis establishment, where the metal is utilized for the synthesis of various iron-containing proteins in both the plant and the bacteroid. Unfortunately, in spite of its importance, iron is poorly available to plant uptake since its solubility is very low when in its oxidized form Fe(III).