Phytohormone Profiling Method for Rice: Effects of GA20ox Mutation on the Gibberellin Content of Japonica Rice Varieties

Abstract

Gibberellins (GAs) are a very important group of phytohormones involved in seed germination, vegetative growth, flowering, and fruit development, being only 4 of the 136 known bioactives: GA 1 , GA 3 , GA 4 , and GA 7 . It has been evidenced that mutations in the OsGA20ox-2 gene produce rice ( Oryza sativa ) dwarf varieties, which were one of the main pillars of the green revolution. In this work two main objectives were proposed: (i) develop a rapid and broad phytohormone profiling method and (ii) to study the effects on the GA content of the GA20ox-2 mutation in several rice developmental stages using three varieties (tall variety, elite variety, mutated variety). A phytohormone extraction using an SPE step and HPLC-MS/MS detection using a QqQ instrument was determined which resulted in limits of detection (LOD) and limits of quantification (LOQ) for GAs that varied between 0.1–0.7 and 0.3–2.3 pg ⋅ g -1 (f.w.) of rice sample, respectively, allowing highly sensitive phytohormones detection in samples. Moreover, a good reproducibility was obtained for the GAs as relative standard deviations (RSD) for a 40 ng ⋅ mL -1 pattern varied between 0.3 and 0.9%. Notoriously, GA 1 was absent in the coleoptile and GA 4 was the GA with higher content in the majority of developmental stages. We also observed a large content increase of the four bioactive GAs in the internode of the flag leaf of the mutated variety allowing to reach same height as the elite variety. Therefore, we provide a rapid and broad phytohormonal profiling method and evidence that the GA20ox-2 mutation is not the only factor generating dwarf varieties. To our knowledge, this is the first study that it has been reported such a high number of simultaneously analyzed gibberellins in rice samples ( Oryza sativa ssp. japonica) in different tissues of different growth stages.

Role of Bacilli in phytohormone production in rice and grain under different doses of vegetative and generative fertilizer

“…In the current study, over time, the GAs showed a tendency to elevate from the vegetative to the generative phase. This result was similar to López-Cristoffanini et al (2019), who reported that in Oryza sativa var. japonica cv.…”

Effect of Trichoderma spp on Plant Height of Local Rice Varieties in the Early Phase of Growth

“…Ten local varieties tested also showed differences in height Ten local varieties tested also showed differences in height [35]. Application GA on three varieties of rice japonica mediterania NRVC980385, Bomba and Dwarf -Bomba shows that Bomba variety is significantly higher than the other two varieties [36]. 86,1 b Number followed by the same letter not significant at the 5% level by DNMRT Plant height is not only a decisive factor in plant architecture, but also an important agronomic trait that is directly linked to the harvest index and yield potential.…”

Combined Linkage Mapping and BSA to Identify QTL and Candidate Genes for Plant Height and the Number of Nodes on the Main Stem in Soybean

“…GA20ox, GA3ox, GA2ox and EUI1 together form a feedback transcriptional control mechanism to maintain the homeostasis of GA content in plants. Inhibition or loss of function of the GA20ox gene results in dwarfing of the plant [45,46]. This may be an important candidate gene for PH in soybean.…”