Anther dehiscence is regulated by gibberellic acid in yellow lupine (Lupinus luteus L.)

Abstract

Background Anther dehiscence resulting in the release of pollen grains is tightly regulated in a spatiotemporal manner by various factors. In yellow lupine (Lupinus luteus L.), a species that shows cleistogamy, the anthers split before the flowers open, but the course and regulation of this process are unknown. The specific control of anther development takes place via hormonal pathways, the wide action of which ensures reproductive success. In our previous research concerning flower and early pod development in yellow lupine, we showed that the lowest transcript level of LlDELLA1, a main repressor of gibberellin (GA) signalling, occurs approximately at the time of anther opening; therefore, the main purpose of this study was to precisely investigate the gibberellic acid (GA3)-dependent regulation of the anther dehiscence in this species. Results In this paper, we showed the specific changes in the yellow lupine anther structure during dehiscence, including secondary thickening in the endothecium by lignocellulosic deposition, enzymatic cell wall breakdown at the septum/stomium and cell degeneration via programmed cell death (PCD), and identified several genes widely associated with this process. The expression profile of genes varied over time, with the most intense mRNA accumulation in the phases prior to or at the time of anther opening. The transcriptional activity also revealed that these genes are highly coexpressed and regulated in a GA-dependent manner. The cellular and tissue localization of GA3 showed that these molecules are present before anther opening, mainly in septum cells, near the vascular bundle and in the endothecium, and that they are subsequently undetectable. GA3 localization strongly correlates with the transcriptional activity of genes related to GA biosynthesis and deactivation. The results also suggest that GA3 controls LlGAMYB expression via an LlMIR159-dependent pathway. Conclusions The presented results show a clear contribution of GA3 in the control of the extensive anther dehiscence process in yellow lupine. Understanding the processes underlying pollen release at the hormonal and molecular levels is a significant aspect of controlling fertility in this economically important legume crop species and is of increasing interest to breeders.

Plant Development and Crop Yield: The Role of Gibberellins

“…Indeed, both the jasmonates-related repressor proteins JASMONATE ZIM-DOMAIN (JAZ) and DELLA act synergistically to repress filament development [ 153 ]. The SWOLLEN ANTHER WALL 1 ( SAW1 ) zinc-finger TF enhances GA20ox3 expression in rice promoting microspore and anther development and dehiscence through GAMYB , while the same GAMYB gene is the target of miRNA159 in yellow lupin controlling pollen release [ 154 , 155 ]. In the presence of GA and jasmonates, MYC2 induces TERPENE SYNTHASE genes TPS11 and TPS21 , permitting the emission of volatile sesquiterpenes necessary for flower development [ 156 ].…”

The Oncidium Ethylene Synthesis Gene Oncidium 1-Aminocyclopropane-1 Carboxylic Acid Synthase 12 and Ethylene Receptor Gene Oncidium ETR1 Affect GA–DELLA and Jasmonic Acid Signaling in Regulating Flowering Time, Anther Dehiscence, and Flower Senescence in Arabidopsis

“…JA is thought to play an important role in regulating anther dehiscence (Sanders et al, 2000;Zhao and Ma, 2000;Ishiguro et al, 2001;Scott et al, 2004), and mutations in genes that participate in JA biosynthesis, such as DAD1 and OPR3, cause a similar delay in anther dehiscence (Sanders et al, 1999(Sanders et al, , 2000Stintzi and Browse, 2000;Scott et al, 2004). GA also regulates anther dehiscence in yellow lupine (Lupinus luteus L.) by regulating genes involved in controlling anther structure such as secondary thickening in the endothecium (Marciniak and Przedniczek, 2021). Since we have shown that 35S::OnACS12 can suppress GA levels and upregulate the accumulation of DELLA proteins, the exploration of the relationship between 35S::OnACS12 and JA biosynthesis was necessary.…”

Comparative Transcriptome Analysis Reveals Hormone Signal Transduction and Sucrose Metabolism Related Genes Involved in the Regulation of Anther Dehiscence in Photo-Thermo-Sensitive Genic Male Sterile Wheat

“…In the study, genes of the auxin signaling pathway were differentially expressed between fertile and sterile conditions. Marciniak’s results revealed that GA3 contributed to the control of anther dehiscence process in yellow lupine [ 39 ]. In our study, some genes of the GA signaling pathway were differentially expressed during anther dehiscence period under two conditions.…”