How Seed Treatment with Plant Hormones Helps Corn Grow in Salty Soil

Jenn Hoskins
26th July, 2024

How Seed Treatment with Plant Hormones Helps Corn Grow in Salty Soil

Image Source: Natural Science News, 2024

Key Findings

  • The study by the Centre of Biotechnology of Borj-Cedria (CBBC) found that salt stress reduces maize seed germination and seedling growth
  • Priming maize seeds with indole-3-acetic acid (IAA) significantly improved germination rates and early seedling growth under salt stress
  • IAA-primed seedlings showed enhanced water uptake, higher sugar content, and increased activity of the enzyme α-amylase, which helps break down starch into sugars
The stages of germination and seedling establishment are critical for the growth and productivity of staple crops. Adverse conditions such as salt stress can severely hinder these processes, reducing crop yields. One promising approach to counteract these effects is seed priming, a pre-sowing treatment that enhances seed vigor and germination performance. A recent study conducted by the Centre of Biotechnology of Borj-Cedria (CBBC) explored the effectiveness of seed priming with indole-3-acetic acid (IAA) in mitigating salt stress in maize (Zea mays L.) seedlings[1]. Salt stress poses a significant challenge to agriculture by reducing seed germination rates and inhibiting seedling growth. This study found that unprimed maize seeds exposed to salt stress exhibited lower germination indices and reduced growth of both the radicle (the embryonic root) and coleoptile (the protective sheath covering the emerging shoot). Additionally, tissue hydration levels were adversely affected. However, when maize seeds were primed with IAA, a naturally occurring plant hormone known for its role in growth and development, the adverse effects of salt stress were significantly alleviated. Primed seeds showed improved germination dynamics, better early seedling establishment, and enhanced water status. The study also revealed that IAA-primed seedlings exhibited higher activity of α-amylase, an enzyme crucial for breaking down starch into sugars. This enzymatic activity led to increased sugar content in the roots and coleoptiles of salt-stressed plants, providing an essential energy source for growth under stress conditions. The benefits of IAA-seed priming extended beyond improved germination and growth. The study observed that IAA priming stimulated the accumulation of endogenous IAA in salt-stressed seedlings. This accumulation played a significant role in detoxifying reactive oxygen species (ROS) and preventing lipid peroxidation, a process that can damage cell membranes. Enhanced activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) were noted, which helped in mitigating oxidative stress. These enzymes were differentially regulated in roots and coleoptiles, indicating a targeted response to salt stress. This study builds on previous research that has shown the effectiveness of various treatments in improving plant tolerance to abiotic stresses. For instance, exogenous melatonin has been found to enhance seed germination under salt stress by regulating nutrient utilization and hormone levels in Limonium bicolor seeds[2]. Similarly, salicylic acid (SA) has been shown to alleviate zinc stress in alfalfa plants by boosting photosynthesis, antioxidant activity, and proline and soluble sugar levels[3]. The current study on IAA-seed priming in maize adds to this body of knowledge by demonstrating another effective method to enhance crop resilience under salt stress. In rice, comparative proteomic analysis has identified specific proteins involved in seed imbibition under salt stress, providing insights into the mechanisms of salt tolerance during germination[4]. The current study on maize with IAA-seed priming complements these findings by highlighting the role of IAA in modulating multiple signaling pathways during early seedling stages, thus enhancing salt tolerance. In conclusion, the study conducted by the CBBC demonstrates that IAA-seed priming is a promising technique to improve maize seedling performance under salt stress. By enhancing germination dynamics, increasing sugar content, and boosting antioxidant enzyme activities, IAA-seed priming equips maize seedlings with better resilience against adverse conditions. This approach could be a valuable addition to green technologies aimed at improving crop yields in salt-affected soils.

AgricultureBiochemPlant Science

References

Main Study

1) Effect of seed priming with auxin on ROS detoxification and carbohydrate metabolism and their relationship with germination and early seedling establishment in salt stressed maize

Published 25th July, 2024

https://doi.org/10.1186/s12870-024-05413-w

Related Studies

2) Exogenous melatonin improves seed germination in Limonium bicolor under salt stress.

https://doi.org/10.1080/15592324.2019.1659705

3) Salicylic acid alleviates Zn-induced inhibition of growth via enhancing antioxidant system and glutathione metabolism in alfalfa.

https://doi.org/10.1016/j.ecoenv.2023.115500

4) Proteomic Analysis Reveals Proteins Involved in Seed Imbibition under Salt Stress in Rice.

https://doi.org/10.3389/fpls.2016.02006


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