Expression of Puroindoline a in Durum Wheat Affects Milling and Pasting Properties

Abstract

Durum wheat has limited culinary utilizations partly due to its extremely hard kernel texture. Previously, we developed transgenic durum wheat lines with expression of the wildtype Puroindoline a ( Pina ) and characterized PINA’s effects on kernel hardness, total flour yield and dough mixing properties in durum wheat. The medium-hard kernel texture is potentially useful for exploring culinary applications of durum wheat. In the present study, we examined the milling parameters and flour attributes of the transgenic lines, including particle size distribution, damaged starch and water binding capacity. PINA expression results in increased break and reduction flour yield but decreased shorts. PINA expression also leads to finer flour particles and decreased starch damage. Interestingly, PINA transgenic lines showed increased peak viscosity and breakdown viscosity but leave other flour pasting parameters generally unaltered. PINA transgenic lines were associated with increased small monomeric proteins, appearing to affect gluten aggregation. Our data together with several previous results highlight distinct effects of PINs on pasting properties depending on species and variety. The medium-hard kernel texture together with improved pasting parameters may be valuable for producing a broader range of end-products from durum wheat.

Toward the Genetic Basis and Multiple QTLs of Kernel Hardness in Wheat

“…Numerous studies have been focused on mining allelic variations and the genotype-phenotype association of Pin, resulting in the identification of 26 alleles of Pina, 33 alleles of Pinb and a few double null alleles [21,22,[77][78][79][80][81][82][83][84][85][86][87]. Manipulation of the expression or genotypes of Pin not only modifies kernel hardness and milling properties in common and durum wheat lines [62][63][64]67,[88][89][90][91][92], but also changes some parameters of the end-use quality and storage protein interaction [29,[93][94][95]. Owing to its importance, research regarding Pin has been comprehensively reviewed by Bhave et al [21,22] in aspects of its genetics, polymorphism identification and studies about its biological functions.…”

Dissection of a novel major stable QTL on chromosome 7D for grain hardness and its breeding value estimation in bread wheat

“…Manipulation of the level of grain hardness not only modifies milling properties in common and durum wheat lines ( Li et al., 2014 ; Wang et al., 2019a ), but also changes some parameters of the end-use quality and storage protein interaction ( Kiszonas and Morris, 2018 ; Wang et al., 2019b ). The previous studies reported that Pin genes could only explain over 60% of the trait’s variation and hinder the identification of other QTLs with minor effects in the bi-parental mapping population ( Sourdille et al., 1996 ; Campbell et al., 1999 ).…”

Features and Possible Applications of Plant Lipid-Binding and Transfer Proteins

“…As shown, wheat puroindolines PIN-a and PIN-b play an important role in the grain texture and are markers available to improve wheat hardness in breeding programs [ 126 ]. The expression of both Pina and Pinb genes, encoding puroindolines PIN-a and PIN-b, is necessary for the soft-kernel phenotype, whereas deletion or loss-of-function mutations in any of these genes lead to hard endosperms [ 127 ]. The presence of starch-bound PIN-a and PIN-b (friabilin) rather than total PINs’ content affects the hardness of wheat grains [ 128 ].…”