Overexpression of AGAMOUS-like gene PfAG5 promotes early flowering in Polypogon fugax

Abstract

<jats:title>Abstract</jats:title> <jats:p><jats:bold>Background</jats:bold>: Herbicides are the major tool for controlling large populations of yield depleting weeds. However, overreliance on herbicides has resulted in weed adaptation and herbicide resistance. In recent years, early flowering weed species related to herbicide resistance is emerging, which may cause seed loss before crop harvest, creating a new problem for non-chemical weed management. However, mechanisms regulating early flowering in weedy species is rarely investigated. <jats:bold>Results</jats:bold>: The MADS-box gene family plays an important role in flowering time regulation and floral organogenesis. In this study, a homolog gene of <jats:italic>AGAMOUS</jats:italic> sub-family<jats:italic> </jats:italic>(referred to as <jats:italic>PfAG5</jats:italic>) of the MADS-box family was cloned from<jats:italic> </jats:italic>plants of<jats:italic> </jats:italic>an early<jats:italic> </jats:italic>flowering<jats:italic> Polypogon fugax </jats:italic>population resistant to the ACCase inhibitor herbicide (clodinafop-propargyl). The<jats:italic> PfAG5</jats:italic> gene was functionally characterized in <jats:italic>Arabidopsis thaliana</jats:italic>. Over-expression of the <jats:italic>PfAG5</jats:italic> gene in Arabidopsis resulted in early flowering with abnormal flowers (e.g. small petals, short plants and reduced seed set) compared to the wild type. The expression of the <jats:italic>PfAG5</jats:italic> gene was high in leaves and flowers, but low in pods in transgenic Arabidopsis. The <jats:italic>PfAG5</jats:italic> gene was earlier and higher expressed in the resistant (R) than the susceptible (S) <jats:italic>P. fugax</jats:italic> plants. Furthermore, one protein (<jats:italic>FRIGIDA</jats:italic>-like protein) interacting with <jats:italic>PfAG5 </jats:italic>in R <jats:italic>P. fugax</jats:italic> was identified by the yeast two-hybrid system with relevance to flowering time regulation. <jats:bold>Conclusions</jats:bold>: These results suggest that the <jats:italic>PfAG5</jats:italic> gene is involved in modulating early flowering in <jats:italic>P. fugax</jats:italic>. This study provides the first evidence for the regulation mechanism of early flowering in an herbicide resistant weed species.</jats:p>

Expression of the Populus Orthologues of AtYY1, YIN and YANG Activates the Floral Identity Genes AGAMOUS and SEPALLATA3 Accelerating Floral Transition in Arabidopsis thaliana

“…The overexpression of several transcription factor genes including FT, and the MADS-box genes AG and SEP3 causes leaf curling and earlier flowering in Arabidopsis [36][37][38][39]. The function of AG and SEP3 orthologues, such as from lavender (Lavandula angustifolia) [40], lily (Lilium longiflorum, Lilium formosanum, and Oriental Lilium Hybrid) [41][42][43][44][45], orchid (Oncidium Gower Ramsey) [43], Japanese gentian (Gentiana scabra) [46], Polypogon fugax [47], pecan (Carya illinoinensis) [48], wheat (Triticum aestivum) [49], London plane (Platanus acerifolia) [50], peach (Prunus persica) [51],…”