Comparative study of the effect of salt stress, Alternaria alternata attack or combined stress on the Cakile maritima growth and physiological performance

Cakile maritima is a halophytic plant model that is well known by its ability to tolerate high salt concentrations. Salinity was reported to improve the tolerance of halophytes to several abiotic stresses; however, the involvement of salt in the tolerance to biotic stress is still scant. In the present work, the effect of salt on C. maritima responses towards the pathogenic Alternaria alternata was investigated. For that, C. maritima seeds were germinated for four weeks. Plants were then divided into four groups: i) Plants irrigated with salt (200mM NaCl); ii) Plants infested by fungus; iii) Plants irrigated with salt and infested by fungus and finally control plants (0mM NaCl, without inoculation). Our results showed that upon salt stress or fungal attack, plants reduced biomass production, hydration status and photosynthetic performance which were associated with a decrease in the gas exchange and chlorophyll fluorescence parameters, with a more pronounced effect upon fungal attack. However, under combined stress, a significant increase of these parameters was noticed, with a level close to that of control. Concerning nutrient contents, K, Zn, Fe, Cu and Mg decreased in the C. maritima leaves exposed to both stresses applied individually. In contrast, all these nutrients were increased in plants grown under combined stress. Taken together, we can conclude that plants grown under combined stresses had better growth rate and physiological performance compared to all other treated plants, and that salt may be the key in improving the C. maritima ability to tolerate fungal attack.

Introduction pages

The papers published in Notulae Botanicae Horti Agrobotanici Cluj-Napoca, Issue 3, Volume 49, 2021 represent new exciting researches in different topics of life science, respectively in plant science, horticulture, agronomy and crop science. Among the interesting articles we invite you to find news about: Recent advancements on use of CRISPR /Cas9 in maize yield and quality improvement; Genome-wide investigation of Hydroxycinnamoyl CoA: Shikimate Hydroxycinnamoyl Transferase (HCT) gene family in Carthamus tinctorius L.; Identification of SNPs in rice GPAT genes and in silico analysis of their functional impact on GPAT proteins; Extensive transcriptome changes underlying the fruit skin colour intensity variation in purple eggplant; Physiological variation of irradiated red radish plants and their phylogenic relationship using SCoT and CDDP markers; Alterations in leaf anatomy, quality, and quantity of flavonols and photosynthetic pigments in Nigella sativa L. subjected to drought and salinity stresses; Impact of the foliar application of nanoparticles, sulfate and iron chelate on the growth, yield and nitrogen assimilation in green beans; Phytotoxicity and allelopathic potential of extracts from rhizomes and leaves of Arundo donax, an invasive grass in neotropical savannas; Comparative study of the effect of salt stress, Alternaria alternata attack or combined stress on the Cakile maritima growth and physiological performance, etc. The Impact Factor communicated by ISI Clarivate (June 30, 2021), is IF 2020 = 1.444 (position 157 of 235 journals, Q3 in Plant Sciences). The metrics in Scopus – Elsevier (June 2, 2021): CiteScore 1.7 (#40/86 in Horticulture).

Endophytic Bacterial Isolates From Halophytes Demonstrate Phytopathogen Biocontrol and Plant Growth Promotion Under High Salinity

Halophytic endophytes potentially contribute to the host’s adaptation to adverse environments, improving its tolerance against various biotic and abiotic stresses. Here, we identified the culturable endophytic bacteria of three crop wild relative (CWR) halophytes: Cakile maritima, Matthiola tricuspidata, and Crithmum maritimum. In the present study, the potential of these isolates to improve crop adaptations to various stresses was investigated, using both in vitro and in-planta approaches. Endophytic isolates were identified by their 16S rRNA gene sequence and evaluated for their ability to: grow in vitro in high levels of NaCl; inhibit the growth of the economically important phytopathogens Verticillium dahliae, Ralstonia solanacearum, and Clavibacter michiganensis and the human pathogen Aspergillus fumigatus; provide salt tolerance in-planta; and provide growth promoting effect in-planta. Genomes of selected isolates were sequenced. In total, 115 endophytic isolates were identified. At least 16 isolates demonstrated growth under increased salinity, plant growth promotion and phytopathogen antagonistic activity. Three showed in-planta suppression of Verticillium growth. Furthermore, representatives of three novel species were identified: two Pseudomonas species and one Arthrobacter. This study provides proof-of-concept that the endophytes from CWR halophytes can be used as “bio-inoculants,” for the enhancement of growth and stress tolerance in crops, including the high-salinity stress.

Halophytes of the Mediterranean Basin—Underutilized Species with the Potential to Be Nutritious Crops in the Scenario of the Climate Change

Halophyte plants are adapted to saline environments and represent a novel type of crops given their possible uses at both culinary and industrial levels. In this work, the nutritional quality of different Mediterranean halophyte species, Atriplex halimus, Salicornia fruticosa, and Cakile maritima, was evaluated under conditions of high salinity. For this, plants were grown at different NaCl concentrations (0, 100, 200, and 300 mM) and the contents of proteins, total lipids, polyphenols, and mineral elements were analyzed as well as growth. Of the three species, C. maritima was the most sensitive to salt stress and therefore showed the highest phenolic compounds content. By contrast, whereas salinity increased the amounts of proteins and phenolics with respect to the control in A. halimus and S. fruticosa, it decreased them in C. maritima. Plants of A. halimus accumulated higher amounts of Na+ in their leaves, but the level of this ion, considering human consumption, was below that of other culinary halophyte species. In conclusion, all the results indicate that these three halophyte species grown at high salt levels represent optimal crops for—new foodstuff—production as green salt or spice due to their nutritional potential.