New studies have discovered an important protein named bGLU25. This protein plays a major role in controlling the way plants adjust their flowering time according to the abundance of this key element. The study, performed in Arabidopsis, reveals a tantalizing discovery. Specifically, it demonstrates that bGLU25 functions as a molecular switch, adapting its activity based on the nutrient milieu. Under phosphorus abundant conditions, bGLU25 localizes to the endoplasmic reticulum. When phosphorus is low, an intriguing cascade of events unfolds that affects the timing of flowering.
Under phosphorus limiting conditions, the protein SCPL50 cleaves bGLU25, which leads to its release into the cytosol. In the cytosol, bGLU25 associates with another protein called AtJAC1. The postulated functional bGLU25-AtJAC1 complex stabilizes GRP7 in a substrate-trapping conformational complex. This protein typically promotes the regulation of FLOWERING LOCUS C (FLC), a master repressor that inhibits premature flowering from occurring.
bGLU25 works by preventing GRP7 from entering the nucleus. This inhibits GRP7 from repressing FLC, which subsequently increases FLC’s activity. This mechanism postpones flowering, helping plants maintain reproductive investment during times when phosphorus is low. To survive nutrient stress, the plant is able to rapidly flip a molecular switch by translocating bGLU25 from the endoplasmic reticulum to the cytosol. This action mimics how plants acclimate to adverse environmental extremes.
Hatem Rouached, doctoral student and one of the lead researchers on this discovery from the Department of Horticultural Science at N.C.
“This is the first time we have seen such a direct link between nutrient status, protein movement inside the cell, and control of flowering time,” – Hatem Rouached.
Rouached added that this study is a great demonstration of how plants combine different signals from their environment and translate it into the developmental decision.
“It is an elegant example of how plants integrate environmental signals into developmental choices,” – Hatem Rouached.
The ramifications of this find reach far beyond fundamental plant biology. Figuring out how plants adjust their flowering times to match when nutrients are available has the potential to greatly improve agricultural practices.
“This discovery helps explain how plants translate nutrient stress into developmental timing. By understanding that mechanism, we can begin designing crops that flower and yield optimally even in nutrient-poor environments,” – Hatem Rouached.
Additionally, the scientists propose this mechanism is more widespread than just Arabidopsis. Similar processes appear to operate in other species, including rice and various crops, suggesting broader applications for improving agricultural resilience in areas facing phosphorus deficiencies.
“We have already seen evidence that a similar process operates in rice and other crop species. That opens exciting possibilities for improving agricultural resilience in phosphorus-deficient regions,” – Hatem Rouached.