Osmotin, a pathogenesis related (PR) protein belonging to PR-5 protein family is induced in plants exposed to various biotic and abiotic stresses. To evaluate the potential involvement of Osmotin in improving resistance to early blight of potato, transgenic lines of an important processing grade potato cultivar ‘Kufri Chipsona 1’ were developed. The integration of T-DNA was confirmed by amplification of 900 bp DNA fragment of Osmotin (OsmWS) gene. The regenerated microshoots were subjected to GUS assay and eight independent putative transgenic lines showing uniform expression of reporter gene were selected for further assessment. The selected lines (L1–L8) were hardened and transferred to the containment facility. The transgenic plants inoculated with spore suspension of Alternaria solani over-expressed OsmWS gene by about 22 folds after three days. The disease severity also decreased in the transgenic lines as the lesion diameter was significantly reduced in comparison to control plants after 8 days of inoculation. Although, variation in disease severity among the transgenic lines was observed, yet, all the transgenic lines over-expressing OsmWS gene showed decreased disease severity and disease incidence. As a measure of plant health, total chlorophyll content and osmotic potential were also measured. Following infection, higher chlorophyll content (160.2 mg/g FW to 252.32 mg/g FW) was recorded in the transgenic lines in comparison with control plants (114.48 mg/g FW). However, an inverse variation was observed in terms of osmotic potential, where infection causes a significant decrease in osmotic potential in some of the transgenic lines. Thus it seems that over-expression of OsmWS gene in potato have potential to confer certain degree of resistance to early blight.

Osmotin是属于PR-5蛋白家族的一种与病程相关的蛋白（PR），在暴露于各种生物和非生物胁迫的植物中被诱导。为了评估渗透调节剂对提高马铃薯对早疫病的抗性的潜力，开发了一种重要加工级马铃薯品种“ Kufri Chipsona 1”的转基因品系。通过扩增Osmotin（OsmWS）基因的900 bp DNA片段，证实了T-DNA的整合。将再生的微芽进行GUS测定，并选择显示报告基因均匀表达的八个独立的推定转基因品系用于进一步评估。选定的管线（L1-L8）进行了硬化，然后转移到安全壳中。接种链格孢菌悬浮液的转基因植物三天后，OsmWS基因过度表达了约22倍。接种8天后，与对照植物相比，病变直径明显减小，因此转基因品系中的疾病严重性也降低了。尽管在转基因品系中观察到疾病严重程度的变化，但是，所有过表达OsmWS的转基因品系该基因显示疾病严重程度和疾病发生率降低。作为植物健康的量度，还测量了总叶绿素含量和渗透势。感染后，与对照植物（114.48 mg / g FW）相比，转基因品系中记录到较高的叶绿素含量（160.2 mg / g FW至252.32 mg / g FW）。然而，在渗透势方面观察到相反的变化，其中感染在一些转基因品系中引起渗透势的显着降低。因此，似乎在马铃薯中OsmWS基因的过表达具有赋予对早疫病一定程度的抗性的潜力。