Recent Advances in Understanding the Function of the PGIP Gene and the Research of Its Proteins for the Disease Resistance of Plants

Polygalacturonase-inhibiting protein (PGIP) is an important plant biochemical anti-disease factor. PGIP has a leucine-rich repeat structure that can selectively bind and inhibit the activity of endo-polygalacturonase (endo-PG) in fungi, playing a key role in plant disease resistance. The regulation of PGIP in plant disease resistance has been well studied, and the effect of PGIP to increase disease resistance is clear. This review summarizes recent advances in understanding the PGIP protein structure, the PGIP mechanism of plant disease resistance, and anti-disease activity by PGIP gene transfer. This overview should contribute to a better understanding of PGIP function and can help guide resistance breeding of PGIP for anti-disease effects.

Temporal expression of a PGIP-gene in strawberry cultivars induced by wounding or by Botrytis cinerea infection

The expression of a PGIP gene (polygalacturonase inhibitor protein) was monitored with semi-quantitative (SQ)-RT-PCR in green, white and red berries of the strawberry cultivar Korona upon infection with Botrytis cinerea and wounding. In addition, the PGIP expression in infected white berries was quantified in four additional cultivars. The constitutive expression of PGIP increased from green to red berries in Korona suggesting developmental regulation of the gene. Wounding and fungal infection caused a moderate or a high induction in the PGIP level, respectively. The maximum peak was observed 24 h after the treatments. In the comparative experiment with five cultivars, infection of white berries caused an induction in the PGIP level 24 h after inoculation in four out of five cultivars.