Understanding of Hormonal Regulation in Rice Seed Germination

Abstract

Seed germination is a critical stage during the life cycle of plants. It is well known that germination is regulated by a series of internal and external factors, especially plant hormones. In Arabidopsis, many germination-related factors have been identified, while in rice, the important crop and monocot model species and the further molecular mechanisms and regulatory networks controlling germination still need to be elucidated. Hormonal signals, especially those of abscisic acid (ABA) and gibberellin (GA), play a dominant role in determining whether a seed germinates or not. The balance between the content and sensitivity of these two hormones is the key to the regulation of germination. In this review, we present the foundational knowledge of ABA and GA pathways obtained from germination research in Arabidopsis. Then, we highlight the current advances in the identification of the regulatory genes involved in ABA- or GA-mediated germination in rice. Furthermore, other plant hormones regulate seed germination, most likely by participating in the ABA or GA pathways. Finally, the results from some regulatory layers, including transcription factors, post-transcriptional regulations, and reactive oxygen species, are also discussed. This review aims to summarize our current understanding of the complex molecular networks involving the key roles of plant hormones in regulating the seed germination of rice.

Plant Development and Crop Yield: The Role of Gibberellins

“…Determination of seed dormancy and the optimal moment to initiate germination is critical for improving plant livelihood and avoiding potential threats in the first stages of seedling development. It is well established that GA is the main hormone involved in seed dormancy breakdown, and the ABA/GA balance is the major regulator of seed dormancy and germination in wheat [ 178 ] and rice [ 179 ], with high GA content leading to decreased dormancy. In rice, the interplay between GA and BRs through the activity of LEA genes has also been shown to influence dormancy [ 180 ].…”

Variation of the phenolic composition and a-glucosidase inhibition potential of seeds, soaked seeds, and sprouts of four wild forms and four varieties of common bean (Phaseolus vulgaris)

“…S1) suggested that 19 (1, 3-8, 18, 20, 22, 23, 26, 27, 32, 33, 35, 37, 43, 55) were phenolic acids, 18 (2, 9-11, 13, 15, 16, 21, 29, 34, 40, 50, 51, 57, 59, 60, 63, 64) were isoflavones, three (12,14,47) were flavones, and two (19,24) were dihydroflavonoids. Besides, 18 flavonol glycosides were found, distributed as one myricetin-3-O-glycoside (25), nine kaempferol-3-Oglycosides (28,41,42,44,46,48,53,54,56), three quercetin-3-O-glycosides (31,39,45), one kaempferol-3,7-Odiglycoside (52), and four flavonol glycosides to which a type could not be assigned (17,30,36,49). Also, three flavonol aglycones were found: myricetin (58), quercetin (62), and kaempferol (66) to two chalcones (38,61), and one non-identified type of phenolic compound (65).…”

“…These glycosides, besides diversifying the phenolic composition of sprouts, can play protective roles as antioxidants, as this activity has been well-recognized for them (3). In addition, these types of glycosides also can change the hydrophilicity and chemical stability of receptor molecules, improving the transportation of plant hormones (40) and contributing to the adequate hormone balance, which is needed for germination (41).…”

Karakter Agro-morfologi dan Periode After-ripening Benih Padi Lanras Lokal Potensial asal Timor-Leste

“…After-ripening terjadi karena adanya ketidakseimbangan hormon khususnya ABA dan GA 3 (Zuo dan Xu, 2020). Kedua hormon ini berkaitan erat dengan aktivitas enzim-enzim yang berperan dalam proses perkecambahan benih (Joshi, 2018;Gong et al, 2022). GA 3 berperan dalam aktivasi enzim-enzim hidrolisis yang terjadi setelah imbibisi, dan akan meningkatkan aktivitas metabolisme lainnya, seperti respirasi (Guzmán-Ortiz et al, 2018).…”