Fundamental Techniques to Evaluate the Roles of Ethylene Receptors in Seed Germination Under Salt Stress in Arabidopsis thaliana.

Seed germination plays a critical role in the reproduction, growth, and survival of plants, enabling them to emerge and establish themselves in their environment. During the process of seed germination, plants experience several biotic and abiotic stresses, affecting their growth and development and leading to morphological, physiological, biochemical, and molecular changes. Therefore, studying seed germination is important to understand plant biology and genetics. This chapter elucidates the basic techniques employed to investigate the contrasting roles of two ethylene receptors, ETHYLENE RECEPTOR 1 and 2 (ETR1 and ETR2), in seed germination under salt stress in Arabidopsis thaliana. We begin with an overview of the ethylene receptor family in Arabidopsis, focusing on the overlapping and nonoverlapping roles of ETR1 and ETR2 in regulating physiological functions such as seed germination. The Subheading Methods details the experimental setup, starting with sterilizing the seeds, preparing the plates, and assessing the germination under both no salt and salt conditions, to understanding changes at the molecular level in the seedlings by isolating RNA and assessing the expression of salt-responsive genes by qPCR analysis. The detailed protocol offers strategies for researchers investigating the role of other hormone signaling pathways in seed germination under biotic and abiotic stresses.