Response of Fruit Bagging to Lignin Biosynthesis and Expression of Related Genes in Fruit Peel of Sand Pear (Pyrus pyrifolia Nakai) cv. Cuiguan

Abstract

<jats:p>This study explored the effects of different colored bags (blue, green, white, yellow, orange, and red) on russet deposition on the peel of semi-russet ‘Cuiguan’ pears 10 days after full bloom (DAFB). The process of russeting of the peel and structure of the cork layer were characterized by microscopy and scanning electron microscopy (SEM), followed by the detection of lignin and the activity of enzymes involved in lignin synthesis. The expression of cinnamate-4-hydroxylase, 4-coumarate:coenzyme A ligase, cinnamyl alcohol dehydrogenase, cinnamoyl-CoA reductase, and peroxidase, which were related to phenylalanine ammonia-lyase, was determined via real-time quantitative polymerase chain reaction. Russeting of the outer peel of ‘Cuiguan’ pear accumulated rapidly at 80 DAFB, and a positive relationship between the russet index and lignin content was observed. Red and infrared (IR) ray, partial far-IR light (600–800 nm), and ultraviolet-A light (350–400 nm) promoted russeting in ‘Cuiguan’ pear peel, whereas green light decreased russeting, the russet index, enzymatic activities, and the expression levels of enzymes involved in lignin synthesis. Values of all these factors were higher for ‘Cuiguan’ pears in red bags than for those in bags of other colors. These findings suggested that spectral components affected the synthesis of lignin and the formation of fruit russet. Storage in green bags reduced russeting and improved fruit appearance.</jats:p>

Network of multi-omics reveals the mechanism of russeting under rainwater in pears

“…Deposition of the cork layer showed a downward trend in both russet and semi-russet pears. As reported previously, rain and light treatment may affect proteins of PAL, CCR1, CAD, POD, COMT, and HHT1 of phenylalanine-lignin monomer synthesis for russeting in semi-russet pear (Shi et al, 2019a;Shi et al, 2019b). In the present study, russeting is not only caused by the single lignin biological pathway, but also the interaction of suberin, phenylpropane-lignin(phenols), and cutin biosynthesis, in which suberin and lignin are intensified and cutin synthesis is inhibited.…”

PpMYB36 Encodes a MYB-Type Transcription Factor That Is Involved in Russet Skin Coloration in Pear (Pyrus pyrifolia)

“…Russet skin is a vital trait affecting both fruit quality and stress tolerance in pear. Although several studies on russet pear have enabled a better comprehension of the mechanical causes responsible for this phenomenon ( Heng et al, 2016 ; Shi et al, 2019b ), the genetic and molecular mechanisms underpinning russet skin coloration have not been thoroughly investigated.…”

“…In particular, the russet skin is related to the biosynthesis of lignin, and is regulated in vivo by many structural and regulatory genes ( Wang Y. Z. et al, 2016 ; Shi et al, 2019b ). The structural genes that are directly involved in the biosynthesis of lignins encode phenylalanine ammonia-lyase ( PAL ), cinnamate 4-hydroxylase ( C4H ), 4-coumarate-CoA ligase ( 4CL ), shikimate/quinate hydroxycinnamoyl transferase ( HCT ), coumarate 3-hydroxylase ( C3H ), cinnamoyl CoA reductase ( CCR ), cinnamyl alcohol dehydrogenase ( CAD ), caffeoyl CoA O-methyltransferase ( CCoAOMT ), and caffeic acid/5-hydroxyferulic acid O-methyltransferase ( COMT ) ( Lam et al, 2017 ; Liu et al, 2018 ).…”

Investigations of Multiple Approaches to Reduce Green Spot Incidence in ‘WA 38’ Apple

“…Bagging alters peel biochemistry and reduces russet in Asian pear (Pyrus pyrifolia Nak.) [57,58] and can impact the incidence of storage disorders in 'Fuji' apples [8]. Matsumoto et al [41] demonstrated that fruit bagging reduces the incidence of a preharvest cork spot-like physiological disorder (CSPD) in 'Kurenainoyume' apples.…”