How nano‐iron chelate and arbuscular mycorrhizal fungi mitigate water stress in Lallemantia species: A growth and physio‐biochemical properties.

Background Aims Methods Results Conclusions Water deficit can seriously affect the growth, yield, and biochemical properties of plants; however, the application of nano‐iron chelate and arbuscular mycorrhizal fertilizers in water deficit has been considered one of the most promising methods to improve plant growth and enhance drought tolerance.This study aimed to investigate the effects of nano‐iron chelated (nFe) fertilizer and arbuscular mycorrhizal fungi (AMFs) on the growth, yield, root colonization, mycorrhizal dependency, water use efficiency (WUE), physio‐biochemical properties, and seed biochemical properties of <italic>Lallemantia iberica</italic> and <italic>Lallemantia royleana</italic> species under drought stress.A split‐factorial experiment was conducted using a randomized complete block design with three replications. The main plot consisted of three drought stress levels (according to the depletion of soil available water) of 30% (I1; without stress), 60% (I2; mild stress), and 90% (I3; severe stress). The subplots were the factorial combination of fertilizers (F) (without fertilizer, nano‐iron chelate [nFe], and AMFs) and plant species (S) of <italic>Lallemantia</italic> (<italic>L. iberica</italic> and <italic>L. royleana</italic>).A decrease in the irrigation regime caused a reduction in growth, seed yield, WUE, chlorophyll content, nutrient uptake, seed oil, and mucilage content, as well as an increase in lipid peroxidation and hydrogen peroxide. Compared with nFe, AMF significantly increased root colonization by mycorrhizal fungi in both species across irrigation regimes. Furthermore, AMF inoculation enhanced nutrient uptake, mucilage, oil, and fatty acids by increasing the WUE. Higher mycorrhizal dependency in inoculated plants played an important role in increasing proline and antioxidant activities in the leaves of the host plant. The water stress and fertilization treatments resulted in the highest root colonization, mycorrhizal dependency, proline content, and antioxidant enzyme activities in <italic>L. royleana</italic>, as well as the highest WUE, accumulation of fatty acids, and nutrient uptake was observed in <italic>L. iberica</italic>. Interestingly, the mycorrhization potential of <italic>Lallemantia</italic> sp. is clearly defined.The results highlighted that AMFs can promote <italic>Lallemantia</italic> to increase seed mucilage and oil under water stress. Overall, we found that both <italic>Lallemantia</italic> species responded well to AMF inoculation under water deficit conditions, where nFe was found to be less effective. [ABSTRACT FROM AUTHOR]