Tognacca Rocío Soledad, Ljung Karin, Botto Javier Francisco
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), Buenos Aires C1417DSE, Argentina.
Departamento de Fisiología, Biología, Molecular, y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires C1428EGA, Argentina.
Plants (Basel). 2024 Jan 30;13(3):408. doi: 10.3390/plants13030408.
Light provides seeds with information that is essential for the adjustment of their germination to the conditions that are most favorable for the successful establishment of the future seedling. The promotion of germination depends mainly on environmental factors, like temperature and light, as well as internal factors associated with the hormonal balance between gibberellins (GA) and abscisic acid (ABA), although other hormones such as auxins may act secondarily. While transcriptomic studies of light-germinating seeds suggest that auxins and auxin transporters are necessary, there are still no functional studies connecting the activity of the auxin transporters in light-induced seed germination. In this study, we investigated the roles of two auxin efflux carrier (PIN3 and PIN7) proteins and one auxin influx (AUX1) carrier protein during seed germination. By using next-generation sequencing (RNAseq), gene expression analyses, hormonal sensitivity assays, and the quantification of indole-3-acetic acid (IAA) levels, we assessed the functional roles of PIN3, PIN7, and AUX1 during light-induced seed germination. We showed that auxin levels are increased 24 h after a red-pulse (Rp). Additionally, we evaluated the germination responses of 3, 7, and 1 mutant seeds and showed that PIN3, PIN7, and AUX1 auxin carriers are important players in the regulation of seed germination. By using gene expression analysis in water, fluridone (F), and ABA+F treated seeds, we confirmed that Rp-induced seed germination is associated with auxin transport, and ABA controls the function of PIN3, PIN7, and AUX1 during this process. Overall, our results highlight the relevant and positive role of auxin transporters in germinating the seeds of .
光照为种子提供信息，这些信息对于将种子萌发调节至最有利于未来幼苗成功生长的条件至关重要。种子萌发的促进主要取决于环境因素，如温度和光照，以及与赤霉素（GA）和脱落酸（ABA）之间激素平衡相关的内部因素，尽管其他激素如生长素可能起次要作用。虽然对光萌发种子的转录组学研究表明生长素和生长素转运蛋白是必需的，但仍没有功能研究将生长素转运蛋白的活性与光诱导的种子萌发联系起来。在本研究中，我们调查了两种生长素外流载体（PIN3和PIN7）蛋白和一种生长素内流（AUX1）载体蛋白在种子萌发过程中的作用。通过使用下一代测序（RNAseq）、基因表达分析、激素敏感性测定以及吲哚 - 3 - 乙酸（IAA）水平的定量，我们评估了PIN3、PIN7和AUX1在光诱导种子萌发过程中的功能作用。我们发现红光脉冲（Rp）后24小时生长素水平升高。此外，我们评估了野生型、突变体3、突变体7和突变体1种子的萌发反应，结果表明PIN3、PIN7和AUX1生长素载体是种子萌发调节中的重要参与者。通过对在水、氟啶酮（F）和ABA + F处理的种子中进行基因表达分析，我们证实Rp诱导的种子萌发与生长素运输有关，并且ABA在此过程中控制PIN3、PIN7和AUX1的功能。总体而言，我们的结果突出了生长素转运蛋白在种子萌发中的相关积极作用。
