Studying the biostimulation effect of amino acids indicated their possible role in salt stress mitigation. In this investigation, six exogenous amino acids (alanine (Ala), arginine (Arg), glutamine (Glu), glycine (Gly), methionine (Met), and proline (Pro)) at 0.5 g/L were sprayed to evaluate their impact on lettuce plants cultivated under simulated salt stress conditions. Photosynthetic pigments, ion absorption, endogenous amino acids contents, catalase (CAT), and peroxidase (POD) enzyme activities were determined. A significant alleviation of salt stress was noticed when EAAs were used in the stress-induced plants, and applying Gly, Met, and Pro improved the plant status under salt stress conditions. The highest electric conductivity (568 μS/g) was testified from the control treatment (50 mM NaCl), while applying exogenous amino acids reduced electrical conductivity (EC), and the result was located between 469 and 558 μS/g. AAs alleviated Cl^- anions in the lettuce leaves by 25% in comparison to control plants. Na⁺ cations were alleviated when the stress-induced plants were sprayed with amino acids. In contrast, applying amino acids promoted K⁺ uptake, and Arg presented the highest contents (3226 μg/g). AAs promoted chlorophyll (chl a and chl b) concentrations compared to the control treatment, and Met produced the maximum chl a content, while the carotene (car) contents significantly augmented when Gly, Met, and Pro were applied. AAs were highly generated in non-stressed treatment (Std) compared to the control. Under simulated salinity stress, Met and Pro application enhanced proteinogenic amino acids expression. Compared to Ctl treatment, peroxidase enzyme activities significantly diminished in the other treatments, which fell by over 40% when Gly, Met, and Pro were sprayed.

Field pea genotypes with tall or semi-dwarf height and with regular or semi-leafless type leaves and tendrils differ in their reactions to drought depending on plant growth and development, impacting final seed yield. In the current opinion paper, arguments are presented showing that terminal drought at the post-flowering and maturing stage can be better tolerated by semi-dwarf and semi-leafless plants with a strong vertical standing ability compared to tall and leafy pea genotypes that suffer severe lodging. On the other hand, early drought at the vegetative stage strongly reverses the preference for faster growing and early flowering tall pea plants with regular leaves. It seems that short and semi-leafless plants lose the advantage of their non-lodging ability in early drought conditions. Meanwhile, drought occurring in the middle of the flowering period causes mixed results, whereby either group of pea genotypes can produce higher seed yield depending on local adaptations. This opinion-paper highlights the importance of characterising the impacts of drought stress at various plant developmental stages, separating differential responses of plants to early and terminal drought stress for pea production. The expected timing of drought, which is specific to different regions, must be used in the development of new cultivars with improved seed yield stability.

Lentil is an important legume crop that exhibits substantial variation in flowering time (FT). This trait is controlled by a complex but well-characterized regulatory system in many plant species, in which the Early Flowering 3 (ELF3) gene functions as a repressor of the Flowering Locus T (FT) gene. In the present study, two distinct genes, LcELF3a and LcELF3b, were identified in lentil. Sequencing of the LcELF3a gene confirmed the absence of the elf3 mutation in studied accessions, which causes a truncated polypeptide and a very early-flowering phenotype in lentil plants. Natural genetic variation, consisting of six SNPs and one insertion/deletion (InDel), but lacking the elf3 mutation, was grouped into two haplotypes, A and B, which were significantly associated with late and early flowering time, respectively. Genotyping using the newly developed ASQ marker LcELF3a-SNP3 revealed clear allele discrimination in both a lentil germplasm collection and hybrid breeding lines, identifying the homozygous genotypes aa and bb. The genotyping results with the LcELF3a-SNP3 marker confirmed that lentil accessions were associated with either late or early flowering time. Gene expression analysis using RT-qPCR in hybrid breeding lines and their parental genotypes showed high transcript levels of the LcELF3a and LcFTa1 genes. Expression of the LcELF3a gene gradually declined, while flowering initiation progressed concomitantly with the upregulation of LcFTa1 transcript accumulation. The expression of LcELF3b followed a similar pattern to that of LcELF3a, although at levels approximately four times lower. None of the other three LcFT genes (LcFTa2, LcFTb1/b2, and LcFTc) showed significant associations with flowering time in the hybrid breeding lines and parental genotypes examined. Seed yield was significantly higher in early FT cv.Krapinka and in late FT parent Flip92-36L, and in corresponding breeding lines, with aa and bb genotype of LcELF3a, respectively, whereas no differences were found between early- and late-flowering genotypes in the lentil germplasm collection. Other traits associated with adaptation to local environmental conditions are likely to have a greater influence on seed yield in lentil.