Dry Priming of Maize Seeds Reduces Aluminum Stress

Abstract

Aluminum (Al) toxicity is directly related to acidic soils and substantially limits maize yield. Earlier studies using hormones and other substances to treat the seeds of various crops have been carried out with the aim of inducing tolerance to abiotic stress, especially chilling, drought and salinity. However, more studies regarding the effects of seed treatments on the induction of Al tolerance are necessary. In this study, two independent experiments were performed to determine the effect of ascorbic acid (AsA) seed treatment on the tolerance response of maize to acidic soil and Al stress. In the first experiment (greenhouse), the AsA seed treatment was tested in B73 (Al-sensitive genotype). This study demonstrates the potential of AsA for use as a pre-sowing seed treatment (seed priming) because this metabolite increased root and shoot growth under acidic and Al stress conditions. In the second test, the evidence from field experiments using an Al-sensitive genotype (Mo17) and an Al-tolerant genotype (DA) suggested that prior AsA seed treatment increased the growth of both genotypes. Enhanced productivity was observed for DA under Al stress after priming the seeds. Furthermore, the AsA treatment decreased the activity of oxidative stress-related enzymes in the DA genotype. In this study, remarkable effects using AsA seed treatment in maize were observed, demonstrating the potential future use of AsA in seed priming.

HsfA1a upregulates melatonin biosynthesis to confer cadmium tolerance in tomato plants

“…The cone‐rod homeobox (Crx) has been identified to directly transactivate the nighttime expression of the melatonin biosynthetic gene pineal night‐specific ATPase ( Pina ) and arylalkylamine N ‐acetyltransferase ( Aanat ), which facilitates melatonin synthesis in rat ( Rattus norvegicus ) . In plants, melatonin biosynthetic genes, such as ASMT/COMT , are induced in response to a variety of stresses and phytohormone stimuli . Herein, we found that the tomato transcription factor HsfA1a bound to the COMT1 promoter, inducing its expression and phytomelatonin biosynthesis under Cd stress (Figs and ).…”

“…For example, in rice, Cd‐induced melatonin biosynthesis is significantly decreased in the presence of quercetin supplementation, indicating that COMT might play a more important role than ASMT to synthesize melatonin during Cd stress . Both in rice and grape vine, copper stress upregulates some lignin biosynthesis pathway genes such as COMT, whereas COMT is also upregulated by soil acidity and aluminum stress in maize . Similarly, salt stress upregulates COMT enzyme expression in foxtail millet seedlings, suggesting a potential role for COMT in enhancing salt tolerance .…”

Abscisic acid-deficient sit tomato mutant responses to cadmium-induced stress

“…Subsequently, H 2 O 2 may be detoxified into H 2 O by ascorbate peroxidase (APX) and catalase (CAT), among other peroxidases (Wu et al 2015). The nonenzymatic antioxidants include ascorbic acid and glutathione, as well as vitamins, flavonoids, alkaloids, and carotenoids (Gratão et al 2005;Alcântara et al 2015). Reduced glutathione (GSH) is oxidized to glutathione (GSSG), whereas ascorbate is oxidized into monodehydroascorbate (MDHA) and dehydroascorbate (DHA).…”

Seed priming: An approach towards agricultural sustainability

“…Emergence percentage of haloprimed chilly seeds was significantly higher compared to unprimed seeds under saline conditions (Khan et al, 2009). Priming of maize seeds with ascorbic acid reduced aluminium stress (Alcantara et al,2015). Mahmoudi et al (2012) reported that hydropriming of lettuce reduces the ill effects of NaCl induced stress.…”