Abstract:

The present study was designed to explore the effect of exogenous nitric oxide (NO) on lignification of loquat
(Eriobotrya japonica Lindl. cv. Jiefangzhong) fruits during cold storage. The fruits were fumigated with (0, 5, 15, 25, 35
and 45 μL/L) NO gas. Fruit firmness, juice percentage, total soluble sugar, titratable acid and lignin content, and the enzyme
activities related to lignin metabolism were analyzed during cold storage (5 ℃) of loquat fruits. The results indicated that
nitric oxide treatments delayed the decline of total soluble sugar and titratable acid content. Meanwhile, NO fumigation
inhibited the increase of fruit firmness and the decrease of juice percentage, thereby maintaining better commercial quality
of loquat fruits. Nitric oxide treatments significantly inhibited the activities of phenylalanine ammonialyase (PAL) and
cinnamylalcohol dehydrogenase (CAD), delayed the reduction of total soluble sugar, and inhibited the increase of lignin
content, thus postponing the development of lignification of loquat fruits during cold storage. The treatments with nitric
oxide at 15 and 25 μL/L were more effective.

Key words: loquat fruits, lignification, nitric oxide, phenylalanine ammonialyase, cinnamylalcohol dehydrogenase