Sunflower is recognized as one of the most important oil plants with strong tolerance to drought in the world. In order to study the response mechanisms of sunflower plants to drought stress, gene expression profiling using high throughput sequencing was performed for seedling leaves and roots (sunflower inbred line R5) after 24 h of drought stress (15% PEG 6000). The transcriptome assembled using sequences of 12 samples was used as a reference. 805 and 198 genes were identified that were differentially expressed in leaves and roots, respectively. Another 71 genes were differentially expressed in both organs, in which more genes were up-regulated than down-regulated. In agreement with results obtained for other crops or from previous sunflower studies, we also observed that nine genes may be associated with the response of sunflower to drought. The results of this study may provide new information regarding the sunflower drought response, as well as add to the number of known genes associated with drought tolerance.

Sunflower (Helianthus annuus L.), an important global oilseed crop, demonstrates remarkable tolerance to drought and salinity. Among transcription factors,

Human mining contributes to increasing the release of chromium (Cr) into the environment. For the phytoremediation of soil with high Cr content, sunflower is the right choice because the Cr in its seeds can be removed during the production of sunflower seed oil. However, the high content of Cr in the soil will inhibit the growth of sunflower, so the soil remediation agents commonly used with sunflower planting are ethylene diamine tetraacetic acid (EDTA) and citric acid (CA). This study conducted a meta-analysis on the effects of EDTA and CA on the development of sunflower under Cr stress. It will provide a reference for sunflower to improve Cr-contaminated soil or a reference to produce crops in Cr-polluted cultivated areas. A total of 97 articles were found, and 7 studies were used in this meta-analysis from January 1990 to January 2022. The results showed that EDTA treatment had no effect on the leaf weight, shoot weight and root weight. CA treatment had a positive effect on the leaf weight, shoot weight and root weight. EDTA and CA increased the Cr concentration in the root, leaf and shoot. This study recommends the addition of any chelating agent or activator, but the content of toxic metals in the soil must first be measured carefully. Unfortunately, in this study, we did not obtain a reference dose, and future research should focus on this problem.

Acetolactate synthase (ALS; EC 2.2.1.6) catalyzes the first committed step in branched-chain amino acid (BCAA) biosynthesis and is the molecular target of multiple herbicide classes, including the imidazolinones. Here, we performed a genome-wide characterization of the HaALS gene family in sunflower (Helianthus annuus L.) and investigated genotype-dependent transcriptional responses to imazethapyr. A total of 11 HaALS genes were identified and classified into three phylogenetic clades (Groups A–C). All HaALS proteins contained the conserved TPP_enzyme domains (TPP_enzyme_N, TPP_enzyme_M, and TPP_enzyme_C), and purifying selection (Ka/Ks < 1) indicated strong evolutionary constraint on their core enzymatic function. Promoter analyses revealed abundant cis-regulatory elements associated with diverse stress and signaling inputs, supporting regulatory potential for herbicide-triggered transcriptional modulation. qRT-PCR analysis following imazethapyr application (0, 24, and 48 h) showed pronounced genotype-dependent expression reprogramming between the susceptible (S) and resistant (R) cultivars. In the R genotype, multiple HaALS members were strongly induced after treatment; specifically, HaALS4 reached a ~6-fold increase at 24 h and a >10-fold increase at 48 h, and HaALS11 increased to ~6–7-fold at 24 h while remaining above the baseline at 48 h; several additional paralogs exhibited intermediate induction (~3–8-fold by 48 h). In contrast, the S genotype showed limited changes (typically ~0.8–2-fold). Collectively, these findings define the evolutionary features of the sunflower HaALS family and identify herbicide-responsive paralogs that may contribute to imidazolinone tolerance, providing candidates for functional validation and molecular breeding.