Breeding of Lotus japonicus that can overcome adverse seasonal environment by coupling flowering time and abiotic stresses

Abstract

AbstractManipulation of floral transition may allow for a free change in the duration of plant vegetative and reproductive growth, thus rendering them to avoid adverse seasonal environmental conditions. In this report, we investigated the effect of the stress‐inducible promoter RD29A on driving the rice FT ortholog Hd3a expression in Lotus japonicus ‘MG20’ in response to environmental changes. Constitutive overexpression of Hd3a (HOE) in ‘MG20’ hastened its flowering in contrast to non‐transformed control (wild type; WT), which did not flower in winter hampered by long days and low temperatures. RD29A promoter had low activity under non‐stress conditions and was induced by cold, drought and salinity in transgenic ‘MG20’. Transgenic plants of Hd3a driven by the RD29A promoter (RH) could flower under unfavourable weather conditions that prohibited the flowering of WT plants. In addition, RH transgenic plants exhibited thriving clumps of branching, inflorescence, and pods because of the low temperature‐induced expression of Hd3a. These results demonstrate that inducible expression of florigen has the potential to tackle unfavourable weather conditions and boost plant production.