Chiriotto Tai S, Saura-Sánchez Maite, Barraza Carla, Botto Javier F
Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Agronomía, Universidad de Buenos Aires (UBA), Ciudad Autónoma de Buenos Aires C1417DSE, Argentina.
Plants (Basel). 2023 Jun 21;12(13):2392. doi: 10.3390/plants12132392.
Seed germination is a critical stage for survival during the life cycle of an individual plant. Genetic and environmental cues are integrated by individual seeds to determine germination, mainly achieved through regulation of the metabolism and signaling of gibberellins (GA) and abscisic acid (ABA), two phytohormones with antagonistic roles. Saline and drought conditions can arrest the germination of seeds and limit the seedling emergence and homogeneity of crops. This work aimed to study the function of BBX24, a B-Box transcription factor, in the control of germination of seeds imbibed in saline and osmotic conditions. Seeds of mutant and reporter GUS lines of BBX24 were incubated at different doses of NaCl and polyethylene-glycol (PEG) solutions and with ABA, GA and their inhibitors to evaluate the rate of germination. We found that BBX24 promotes seed germination under moderated stresses. The expression of is inhibited by NaCl and PEG. In addition, ABA suppresses BBX24-induced seed germination. Additional experiments suggest that BBX24 reduces ABA sensitivity, improving NaCl tolerance, and increases GA sensitivity in seeds imbibed in ABA. In addition, BBX24 inhibits the expression of and and genetically interacts upstream of HY5 and ABI5. This study demonstrates the relevance of BBX24 to induce drought and salinity tolerance in seed germination to ensure seedling emergence in sub-optimal environments.
种子萌发是单株植物生命周期中生存的关键阶段。单个种子整合遗传和环境线索来决定萌发，这主要通过调控赤霉素（GA）和脱落酸（ABA）这两种具有拮抗作用的植物激素的代谢和信号传导来实现。盐渍和干旱条件会抑制种子萌发，并限制作物的幼苗出土和整齐度。这项工作旨在研究B-Box转录因子BBX24在控制盐渍和渗透条件下吸胀种子萌发中的功能。将BBX24突变体和报告基因GUS系的种子在不同剂量的NaCl和聚乙二醇（PEG）溶液中，以及与ABA、GA及其抑制剂一起孵育，以评估萌发率。我们发现BBX24在适度胁迫下促进种子萌发。BBX24的表达受到NaCl和PEG的抑制。此外，ABA抑制BBX24诱导的种子萌发。进一步的实验表明，BBX24降低了ABA敏感性，提高了NaCl耐受性，并增加了在ABA处理下吸胀种子对GA的敏感性。此外，BBX24抑制了某些基因的表达，并在遗传上与HY5和ABI5的上游相互作用。这项研究证明了BBX24在种子萌发中诱导干旱和盐渍耐受性以确保在次优环境中幼苗出土的相关性。
