Being a staple food, wheat (Triticum aestivum) nutritionally fulfills all requirements of human health and also serves as a significant link in the food chain for the ingestion of pollutants by humans and animals. Therefore, the presence of the heavy metals such as lead (Pb) and cadmium (Cd) in soil is not only responsible for the reduction of wheat crop yield but also the potential threat for human and animal health. However, the link between DNA methylation and heavy metal stress tolerance in wheat has not been investigated yet. In this study, eight high yielding wheat varieties were screened based on their phenotype in response to Pb stress. Out of these, Pirsabak 2004 and Fakhar-e-sarhad were identified as Pb resistant and sensitive varieties, respectively. In addition, Pirsabak 2004 and Fakhar-e-sarhad varieties were also found resistant and sensitive to Cd and Zinc (Zn) stress, respectively. Antioxidant activity was decreased in Fakhar-e-sarhad compared with control in response to Pb/Cd/Zn stresses, but Fakhar-e-sarhad and Pirsabak 2004 accumulated similar levels of Pb, Cd and Zn in their roots. The expression of Heavy Metal ATPase 2 (TaHMA2) and ATP-Binding Cassette (TaABCC2/3/4) metal detoxification transporters are significantly upregulated in Pirsabak 2004 compared with Fakhar-e-sarhad and non-treated controls in response to Pb, Cd and Zn metal stresses. Consistent with upregulation of metal detoxification transporters, CG DNA hypomethylation was also found at the promoter region of these transporters in Pirsabak 2004 compared with Fakhar-e-sarhad and non-treated control, which indicates that DNA methylation regulates the expression of metal detoxification transporters to confer resistance against metal toxicity in wheat. This study recommends the farmers to cultivate Pirsabak 2004 variety in metal contaminated soils and also highlights that DNA methylation is associated with metal stress tolerance in wheat.

Gladiolus is an ornamental bulbous plant and is commercially propagated in the world through its corms. Usually, a single bud is sprouted from a mother corm but sprouting of multiple buds favors an increase in production of propagules. Thus, present research work was carried out to enhance the sprouting of multiple buds and evaluate its effects on other growth parameters through pre-plant soaking of corms in solution of plant growth regulators. The corms were soaked in solutions of gibberellic acid (GA 3 ), benzyladenine (BA) or ethrel at 0, 50, 100 or 150 ppm concentrations for 24 hrs before planting in the field. Gibberellic acid at 100ppm concentration increased plant height to 105 cm compared to 97.60 cm in control plants, flowering percentage (84.67%), spike length (40.03 cm) and also boosted the corm weight (68.30 g). Soaking of corms in 150 ppm benzyladenine solution enhanced the number of sprouting per corm (2.14) and reduced the plant height (87.00 cm) while 50 ppm concentration of ethrel increased the spike length (42.14 cm). In conclusion, soaking of corms in benzyladenine favored the modifications in various traits of interest including sprouting of multiple buds and an increase in the production of corms while gibberellic acid improved the floral characteristics of gladiolus spikes.

Foliar Application of Growth Bioregulators Influences Floral Traits, Cormassociated Traits and Chemical Constituents in Gladiolus grandiflorus L. bulbous plant;growth enhancement;morphological attributes;polyamines;vitamins; Gladiolus is one of the most popular cut flowers in the world floral market and is highly attractive to consumers. The production of poor-quality gladiolus spikes is one of the most important hurdles to obtaining high prices for this crop. The main objectives of this study were to improve the quantitative characteristics of gladiolus spikes, to increase propagule production and to enhance chemical constituent levels in leaves to help improve plant growth. We performed foliar application of bioregulators, including polyamines (putrescine and spermine) and vitamins (ascorbic acid and thiamine), at different concentrations (0, 0.1, 0.4, 0.7 and 1 mM) to gladiolus plants at the three leaf, five leaf and slipping stages. Application of 1 mM putrescine was the most effective treatment, with prominent effects on economically important spike traits including spike length (55.53 cm), spike diameter (7.53 mm), florets per spike (13.99), first floret diameter (9.66 cm) and first floret weight (4.90 g), followed by spermine treatment. The 1 mM putrescine treatment also had positive effects on corm-associated traits including corm diameter and corm weight, with values of 4.57 cm and 26.16 g compared to 3.47 cm and 17.16 g in control plants, respectively. The contents of chemical constituents in leaves, including total chlorophylls ($8.06mg{\cdot}g^{-1}$), total carotenoids ($1.66mg{\cdot}g^{-1}$), total soluble sugars ($4.75 mg{\cdot}g^{-1}$) and phenolics ($0.89mg{\cdot}g^{-1}$) increased in response to foliar application of 1 mM putrescine compared to the control. Ascorbic acid and thiamine also had positive effects on various plant morphological traits and chemical constituents in leaves compared to control plants, but the growth-promoting effects of polyamines were more pronounced. Hence, applying polyamines to gladiolus leaves will help improve spike production and increasing propagule (cormel) yields.