How Apple Genes Affect Salt Tolerance and Stress Response

Greg Howard
4th July, 2024

How Apple Genes Affect Salt Tolerance and Stress Response

Image Source: Natural Science News, 2024

Key Findings

  • Researchers at Shenyang Agricultural University found that the transcription factor MdERF023 reduces apple plants' salt tolerance
  • MdERF023 interferes with the plant hormone ABA, which is crucial for managing salt stress
  • MdERF023 also disrupts ion balance by reducing the plant's ability to expel sodium and absorb potassium
Salt stress is a significant challenge for apple (Malus × domestica) cultivation, affecting growth and productivity. Recent research from Shenyang Agricultural University[1] has shed light on a transcription factor, MdERF023, which plays a critical role in regulating apple's response to salt stress. This study explores how MdERF023 negatively impacts salt tolerance by interfering with abscisic acid (ABA) signaling and ion homeostasis, providing new insights into potential genetic engineering targets for developing salt-tolerant apple varieties. The study reveals that MdERF023 belongs to the APETALA2/ethylene response factor (AP2/ERF) family, known for its involvement in plant growth and stress responses. The researchers found that overexpressing MdERF023 in apple plants and calli significantly decreased their salt tolerance. This negative impact is linked to the transcription factor's ability to bind directly to the promoter of MdMYB44-like, a gene that positively modulates ABA signaling-mediated salt tolerance, and suppress its transcription. ABA is a crucial plant hormone involved in various stress responses, including leaf senescence and salt stress. Previous studies have shown that ABA can promote leaf senescence through the action of specific proteins like MdbHLH93[2]. However, ABA's role in salt stress tolerance is more complex. The current study demonstrates that by inhibiting MdMYB44-like, MdERF023 disrupts ABA signaling, thereby reducing the plant's ability to cope with salt stress. In addition to its effects on ABA signaling, MdERF023 also downregulates the transcription of MdSOS2 and MdAKT1. MdSOS2 is part of the Salt Overly Sensitive (SOS) pathway, which is essential for expelling excess sodium (Na+) from plant cells, thus maintaining ion balance under salt stress. MdAKT1, on the other hand, is involved in potassium (K+) uptake. The study found that the downregulation of these genes by MdERF023 leads to reduced Na+ expulsion and K+ absorption, further compromising the plant's salt tolerance. The role of potassium channels in stress adaptation has been well-documented. For instance, the K(+) channel PutAKT1 from Puccinellia tenuiflora enhances salt tolerance in Arabidopsis by increasing K(+) content and reducing Na(+) accumulation[3]. The current study aligns with these findings by highlighting the importance of K+ absorption in managing salt stress. However, it also expands on this knowledge by identifying a specific transcription factor that negatively regulates this process in apple plants. Ethylene signaling is another crucial pathway in plant stress responses. Previous research has shown that ethylene signaling can affect salt-stress responses, with certain ethylene receptor mutants displaying altered salt sensitivity[4]. The current study's identification of MdERF023, an ethylene response factor, as a negative regulator of salt tolerance, adds another layer to our understanding of how ethylene signaling intersects with other hormonal and ionic pathways to modulate stress responses. In summary, the study from Shenyang Agricultural University provides valuable insights into the molecular mechanisms underlying salt stress tolerance in apple plants. By identifying MdERF023 as a negative regulator of ABA signaling and ion homeostasis, the research opens up new avenues for genetic engineering aimed at enhancing salt tolerance in apple varieties. This could have significant implications for improving apple cultivation in salt-affected soils, thereby ensuring better yield and productivity.

GeneticsBiochemPlant Science

References

Main Study

1) The transcription factor MdERF023 negatively regulates salt tolerance by modulating ABA signaling and Na+/H+ transport in apple.

Published 3rd July, 2024

https://doi.org/10.1007/s00299-024-03272-1

Related Studies

2) MdbHLH93, an apple activator regulating leaf senescence, is regulated by ABA and MdBT2 in antagonistic ways.

https://doi.org/10.1111/nph.15628

3) Expression of the AKT1-type K(+) channel gene from Puccinellia tenuiflora, PutAKT1, enhances salt tolerance in Arabidopsis.

https://doi.org/10.1007/s00299-010-0872-2

4) Modulation of ethylene responses affects plant salt-stress responses.

Journal: Plant physiology, Issue: Vol 143, Issue 2, Feb 2007


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