Tiny Selenium Particles Boost Tomato Plant Drought Defense by Gene Adjustment

David Palenski
31st January, 2024

Tiny Selenium Particles Boost Tomato Plant Drought Defense by Gene Adjustment

Cherry tomato (Solanum lycopersicum cerasiforme)

Photo adapted from: Kaden Slone / CC BY (Source)
Drought poses a significant challenge to global food production, particularly for crops like tomatoes. Water scarcity leads to reduced yields and can even cause complete crop failure. Researchers at Islamic Azad University, Tehran, recently investigated whether selenium nanoparticles (SeNPs) could help tomato plants withstand drought conditions[1]. This research builds upon previous work demonstrating the potential of selenium to enhance drought tolerance in other crops, such as canola and camelina[2]. That earlier study showed that selenium application improved various physiological and biochemical attributes, ultimately boosting yield even under normal irrigation. The study focused on applying SeNPs directly to the leaves of tomato plants. Plants were either treated with a solution containing 4 mg/L of SeNPs or left untreated as a control. Following a period of initial growth, all plants were subjected to drought stress – a period of reduced watering. The results showed that plants treated with SeNPs exhibited improved growth, higher yields, and a more timely transition to the flowering stage, even when water was limited. A key aspect of drought stress in plants is the build-up of damaging molecules called reactive oxygen species (ROS). These molecules can disrupt cell function. The researchers found that SeNP treatment reduced the accumulation of hydrogen peroxide (H2O2), a type of ROS, suggesting a protective effect against oxidative damage. This aligns with findings from research on mustard plants, which showed that silicon application also helps to reduce ROS production under stress[3]. Both studies highlight the importance of bolstering a plant’s antioxidant defenses to combat the negative effects of environmental stress. The researchers also investigated how SeNPs affect the plant at a molecular level, specifically looking at microRNAs (miRNAs). These are small RNA molecules that regulate gene expression – essentially controlling which genes are turned on or off. They found that a particular miRNA, miR-172, showed different patterns of expression depending on whether plants were treated with SeNPs and whether they were experiencing drought. Under normal conditions, SeNP treatment slightly increased miR-172 expression. However, during drought, miR-172 levels tended to decrease. This suggests that SeNPs may influence plant responses to drought by altering miRNA activity. Other genes, including bZIP transcription factor and CRTISO, were also found to be upregulated, indicating a complex interplay of genetic responses triggered by the SeNP treatment. Furthermore, the study demonstrated that SeNP treatment improved the plant’s ability to maintain the integrity of its cell membranes, a crucial factor in drought tolerance. This was accompanied by increases in both enzymatic (catalase and peroxidase) and non-enzymatic (ascorbate and glutathione) antioxidants, further reinforcing the protective effect of SeNPs. The researchers also observed increased levels of proline, phenylalanine ammonia-lyase, non-protein thiols, and flavonoids – all compounds known to contribute to stress tolerance in plants. Interestingly, the SeNP treatment also enhanced the nutritional quality of the tomatoes, increasing the concentrations of potassium, magnesium, iron, and selenium in the fruit. This suggests that SeNPs not only improve plant survival under drought but also enhance the nutritional value of the crop. The findings from complement research on maize, which identified salt-responsive miRNAs involved in adapting to stress[4][5]. While the stresses differ (salt vs. drought), both studies emphasize the role of miRNAs in mediating plant responses to adverse environmental conditions. The current study expands on this by demonstrating how nanoparticle application can influence miRNA expression and ultimately enhance stress tolerance. The research suggests that foliar spraying with SeNPs represents a promising strategy for mitigating the detrimental effects of drought on tomato production.

AgricultureBiotechPlant Science

References

Main Study

1) Selenium nanoparticles conferred drought tolerance in tomato plants by altering the transcription pattern of microRNA-172 (miR-172), bZIP, and CRTISO genes, upregulating the antioxidant system, and stimulating secondary metabolism.

Published 31st January, 2024

https://doi.org/10.1007/s00709-024-01929-y

Related Studies

2) Selenium Alleviates the Adverse Effect of Drought in Oilseed Crops Camelina (Camelina sativa L.) and Canola (Brassica napus L.).

https://doi.org/10.3390/molecules26061699

3) Silicon-induced postponement of leaf senescence is accompanied by modulation of antioxidative defense and ion homeostasis in mustard (Brassica juncea) seedlings exposed to salinity and drought stress.

https://doi.org/10.1016/j.plaphy.2020.09.038

4) Small RNAs: Big Impact on Plant Development.

https://doi.org/10.1016/j.tplants.2017.09.009

5) Differential expression of miRNAs in response to salt stress in maize roots.

https://doi.org/10.1093/aob/mcn205


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