“Intelligent” seed pellets may improve chilling tolerance in tobacco

Abstract

Tobacco seeds and seedlings often encounter low temperature stress in China. An 'intelligent' tobacco seed pellet was developed to improve chilling tolerance by adding thermo-sensitive PNIPAAm-co-BMA (poly(N -isopropylacrylamide-cobutyl methacrylate)) hydrogel. PNIPAAm-co-BMA can detect changes in environmental temperature and change its reticular structure accordingly. In addition, the release rate of salicylic acid (SA) loaded in PNIPAAm-co-BMA hydrogel is changed. Tobacco seeds of two different chilling-tolerant tobacco varieties were pelleted by SA-loaded PNIPAAm-co-BMA, and then the germination characteristics, seedling quality and some physiological parameters of the seeds and seedlings were measured after a chilling stress at 11 • C for 5 d. The results showed that the germination percentage (GP), germination index (GI), root length, seedling dry weight and the activities of POD (peroxidase) were significantly increased and the concentration of MDA (malondialdehyde) was significantly decreased in the 'intelligent' seed pellets compared with the seeds without SA and PNIPAAm-co-BMA in both varieties. The results showed that the 'intelligent' seed pellets had thermo-sensitive traits; they enhanced and prolonged the efficiency and acting time of loaded SA. This indicated that the 'intelligent' seed pellets pelleted with SA-loaded PNIPAAm-co-BMA could be used to improve chilling tolerance.