The role of the sunflower seed coat and endosperm in the control of seed dormancy and germination: phytohormone profile and their interaction with seed tissues

Abstract

The seed coat is a multifunctional tissue that plays an important role in dormancy and germination of sun ower seeds. In addition, abscisic acid (ABA) and gibberellins (GAs) are the primary phytohormones that antagonistically regulate seed dormancy, although other phytohormones such as auxins (AUX) and Jasmonates (JAs) also play a critical role in the modulation of these processes. Here, we investigated the role of the seed coat in imposition and release of sun ower seed dormancy. We evaluated the endogenous level of ABA, jasmonic acid (JA) and indol-3-acetic acid (IAA) in dry and imbibed seed coats of two inbred Helianthus annuus lines (B123 and B91), and analysed the seed coat anatomy of their dry cypselas. The results showed that the dormancy of B123 seeds is associated with a low content of ABA, JA and IAA in seed coat, and a high content of these phytohormones in the embryo. A dry storage period increased ABA and JA contents in the seed coat, although it decreased them in the embryo. Both the embryo and seed coat showed a reduction in IAA after the storage period. No relevant differences were registered in the histological analysis of the seed coat. Altogether, our results remark the relevance of the interaction between the seed coat and the embryo in the release of dormancy in sun ower seeds.

Seed-Coat Pigmentation Plays a Crucial Role in Partner Selection and N2 Fixation in Legume-Root–Microbe Associations in African Soils

“…Flavonoids secreted by legume seeds play a major role as signal molecules for attracting compatible rhizobia during symbiotic establishment. As the reproductive unit, seeds carry the genetic material of crop species over time and space, and not only does the seed coat play a vital role in protecting the embryo and/or determining seed dormancy and germination [ 74 , 75 , 76 ], it also contains a host of novel compounds that are released following the imbibition of water during germination. These molecules include flavonoids, proteins, peptides, amino acids, alkaloids, and terpenoids [ 65 , 75 ].…”

Seed Coat Pigmentation Plays a Crucial Role in Partner Selection and N2 Fixation in Legume Root-Microbe Associations in African Soils

“…Flavonoids secreted by legume seeds play a major role as signal molecules for attracting compatible rhizobia during symbiotic establishment. As the reproductive unit, seeds carry the genetic material of crop species over time and space, and not only does the seed coat play a vital role in protecting the embryo, and/or determining seed dormancy and germination [70][71][72], it also contains a host of novel compounds which are released following imbibition of water during germination. These molecules include flavonoids, proteins, peptides, amino acids, alkaloids and terpenoids [62,71].…”

An Utilizing Marginal Red Yellow Podzolic Soil as a Growing Medium for Auxin-Soaked Cutting Propagation of Red Master Grapes (Vitis vinifera L)

“…ABA is commonly connected with seed dormancy promotion, whereas GAs are implicated in seed dormancy break and germination promotion. The appropriate regulation of these activities is dependent on the balance of ABA and GA levels, as well as their interactions with other hormones and environmental signals (Del Bel et al, 2023).…”

“…The balance of these hormones is critical for regulating seed dormancy and the transition to germination. The complicated interaction of auxin with ABA and GAs aids in the fine-tuning of germination time and circumstances (Del Bel et al, 2023) temperature, and moisture levels can influence auxin levels and signaling pathways, altering seed dormancy and germination potential (Sybilska & Daszkowska-Golec, 2023).…”