Barley and uses thereof

Abstract

The invention provides barley grain comprising a reduced level or activity of starch synthase IIa protein and a starch content of at least 41% (w/w) and methods of producing, identifying and using same. The grain may comprise an amylase content of at least 50%, a β-glucan content of 5-9% (w/w) or greater than 9% (w/w), and/or a fructan content of 3-11% (w/w). The fructan may comprise a degree of polymerization from about 3 to about 12. For example, the plant and grain comprises a sex6-292 allele and/or an amo1 mutation. A food or beverage product, and methods of producing a food or beverage product, comprising obtaining or producing the subject grain and processing the grain to produce the product. Also contemplated are methods of improving one or mom indicators of health in a mammal comprising administering a composition comprising the subject barley grain or a product comprising same.

The claims defining the invention re as follows: 
     
         1 . Barley grain comprising a reduced level or activity of SSIIa protein and a starch content of at least 41% (w/w). 
     
     
         2 . The barley grain of  claim 1 , comprising a starch content of at least 43% (w/w), at least 45% (w/w), at least 47% (w/w), at least 50% (w/w), or comprising a starch content of 41-65% (w/w). 
     
     
         3 . The grain of  claim 1  or  2 , comprising an amylose content of at least 50% as a proportion of the total starch in the grain. 
     
     
         4 . The grain of  claim 3 , comprising an amylose content of at least 60% as a proportion of the total starch in the grain. 
     
     
         5 . The grain of any one of  claims 1  to  4 , comprising a β-glucan content of 5-9% (w/w), or greater than 9% (w/w). 
     
     
         6 . The grain of any one of  claims 1  to  5 , comprising a fructan content of 3-11% (w/w), or 4-11% (w/w). 
     
     
         7 . The grain of  claim 6 , wherein the fructan comprises a degree of polymerization from about 3 to about 12. 
     
     
         8 . The grain of any one of  claims 1  to  7  comprising a mutation in an endogenous gene encoding a polypeptide with SSIIa activity wherein the mutation reduces the expression of the gene encoding SSIIa in a barley plant or leads to the expression of SSIIa with reduced level or activity. 
     
     
         9 . The grain of  claim 8  which is homozygous for the sex6-292 allele. 
     
     
         10 . The grain of any one of  claims 1  to  7  wherein the level of SSIIa is reduced by an exogenous nucleic acid molecule which down-regulates the expression of a gene encoding SSIIa in a barley plant. 
     
     
         11 . The grain of  claim 10  wherein the exogenous nucleic acid molecule comprises a gene-silencing chimeric gene, an antisense, ribozyme, co-suppression, dsRNA molecule, hairpin RNA molecule or microRNA that down-regulates endogenous SSIIa expression. 
     
     
         12 . The grain of any one of  claims 1  to  11 , wherein the grain further comprises a genetic variation which reduces the activity of an amo1 gene. 
     
     
         13 . The grain of  claim 12  wherein the genetic variation comprises a mutation in an amo1 gene. 
     
     
         14 . The grain according to any one of  claims 1  to  13 , which is homozygous for the amo1-AC38 allele. 
     
     
         15 . The grain of any one of  claims 1  to  14  which is wholegrain or cracked, ground, polished, milled, kibbled, rolled or pearled grain. 
     
     
         16 . A barley plant capable of producing the grain according to any one of  claims 1  to  15 . 
     
     
         17 . Barley wholemeal or flour produced from the grain according to any one of  claims 1  to  15 . 
     
     
         18 . A method of producing a food or beverage product, wherein the method comprises:
 (i) obtaining or producing barley grain according to any one of  claims 1  to  15 ; and   (ii) processing the grain to produce the product.   
     
     
         19 . The method of  claim 18  wherein the product is selected from the group consisting of wholemeal, flour, starch, bran, β-glucan, fructan, a non-starch polysaccharide, and cracked, ground, polished, milled, kibbled, rolled or pearled grain. 
     
     
         20 . The method of  claim 18  or  19  wherein the processed barley grain is mixed with one or more other ingredients to make the food or beverage product. 
     
     
         21 . The method according to any one of  claims 18  to  20  futher comprising:
 (iii) assessing the level or type of starch, starch content, amylose, amylopectin, β-glucan, fructan, non-starch polysaccharides, dietary fibre, resistant starch in the barley grain or the product therefrom. 
 
     
     
         22 . The method of any one of  claims 18  to  21  wherein the food or beverage product is a grain, flour, breakfast cereal, biscuit, muffin, muesli bar, noodle, a sweetening agent, a low calorie additive, a bulking agent, a dietary fibre, a texturizing agent, a preservative, a probiotic agent or the like or any combination of these. 
     
     
         23 . A method of producing a barley plant capable of producing grain which has a reduced level or activity of SSIIa protein and a starch content of at least 41%, wherein the method comprises: (i) introducing into said plant an agent which down-regulates the level or activity of endogenous starch synthase IIa (SSIIa) in the plant relative to a control plant, or a mutation in an endogenous gene encoding SSIIa in the plant, and (ii) selecting the barley plant which produces said grain and a genetic variation which reduces the activity of an amo1 gene. 
     
     
         24 . The method of  claim 23  comprising introducing into the plant a genetic variation which reduces the activity of an amo1 gene. 
     
     
         25 . The method of  claim 23  wherein the agent comprises a nucleic acid molecule which down-regulates endogenous SSIIa gene expression. 
     
     
         26 . The method of  claim 25  wherein the nucleic acid molecule comprises a gene-silencing chimeric gene, an antisense, ribozyme, co-suppression, dsRNA molecule, hairpin RNA or other exogenous nucleic acid molecule that down-regulates endogenous SSII expression. 
     
     
         27 . The method according to any one of  claims 23  to  26  wherein the method further comprises assessing the level, activity and/or type of starch, starch content, amylose, amylopectin, β-glucan, fructan, non-starch polysaccharide, dietary fibre or resistant starch in the barley grain or a product therefrom, or analysing the plant with one or more genetic markers. 
     
     
         28 . The method of any one of  claims 23  to  27  wherein the reduced level or activity of SSIIa protein is less than 25%, less than 10%, less than 5%, or essentially lacking relative to that of a control plant or the plant prior to the introduction of the agent or mutation. 
     
     
         29 . A method of producing the barley grain of  claims 1  to  15 , comprising the steps of growing a barley plant and harvesting the grain. 
     
     
         30 . The plant or grain or wholemeal or flour of any one of  claims 1  to  17  when used or for use in the production of a product to increase the level of resistant starch, dietary fibre, water soluble carbohydrate, β-glucan, fructan or non-starch carbohydrate in said product or to decrease the glycemic index (GI) of said product. 
     
     
         31 . Use of starch, β-glucan or fructan isolated from a plant, grain, wholemeal or flour of any one of  claims 1  to  17  in a food as a sweetening agent, a low calorie additive, a bulking agent, a dietary fibre, a texturizing agent, a preservative, a probiotic agent or the like or any combination of these. 
     
     
         32 . Use of a grain, flour, wholemeal, starch, β-glucan or fructan isolated from a plant, grain, wholemeal or flour of any one of  claims 1  to  17  in the production of a food product to increase the level of resistant starch, dietary fibre, water soluble carbohydrate, 1-glucan or fructan in said food product or to decrease the glycemic index (GI) of said food product. 
     
     
         33 . Use of  claim 32  wherein the level of amylose, β-glucan and fructan are increased. 
     
     
         34 . A food product comprising a food ingredient at a level of at least 10% on a dry weight basis, wherein the food ingredient is a barley grain of any one of  claims 1  to  15  or wholemeal or flour obtained therefrom wherein the wholemeal or flour comprises a reduced level or activity of SSIIa protein and a starch content of at least 41% (w/w). 
     
     
         35 . The food product of  claim 34  wherein the wholemeal or flour comprises 3-11% fructan (w/w) or 4-11% (w/w) fructan on a weight basis. 
     
     
         36 . The food product of  claim 34  or  35  wherein the wholemeal or flour comprises a β-glucan content of 5-9% (w/w), or greater than 9% (w/w). 
     
     
         37 . The food product of any one of  claims 34  to  36  where the wholemeal or flour comprises 50% or 60% amylose as a proportion of total starch in the wholemeal or flour. 
     
     
         38 . The food product of any one of  claims 34  to  37  wherein the product is selected from the group consisting of bread, buns, breakfast cereal, cake, biscuit, pastry, crackers, muffins, pizza, croissants, bagels, pretzels, pasta, noodles, baking ingredients, baking mixes, soup, sauce, thickening agent, confectionary, and other farinaceous goods. 
     
     
         39 . The product of any one of  claims 34  to  38  wherein the barley comprises the sex6-292 allele. 
     
     
         40 . Use of a grain or flour isolated from a plant or grain of any one of  claims 1  to  17  in the product of a food product to increase the level of starch, starch content, amylose, amylopectin, β-glucan, fructan, non-starch polysaccharide, dietary fibre or resistant starch in the food product. 
     
     
         41 . A method of identifying a variety of barley grain which has increased levels of amylose, and one or more of starch, starch content, amylose, amylopectin, β-glucan, fructan, non-starch polysaccharide, dietary fibre or resistant starch:
 (i) obtaining barley grain which is altered in starch via synthesis or catabolism, 
 (ii) determining the amount of starch, amylose, amylopectin, β-glucan, fructan, non-starch polysaccharide, dietary fibre or resistant starch in the grain, 
 (iii) comparing the level in (ii) to that in a control grain or parental grain; and 
 (iv) if the level of one or more of starch, starch content, amylose, amylopectin, β-glucan, fructan, non-starch polysaccharide, dietary fibre or resistant starch are increased in the altered grain, selecting the grain. 
 
     
     
         42 . The method of  claim 41  which further comprises mutagenesis or plant cell transformation prior to step (i). 
     
     
         43 . A method of determining the amount of fructan in barley grain, comprising the step of obtaining grain according to any one of  claims 1  to  17 , processing the grain so as to extract the fructan, and measuring the amount of extracted fructan so as to determine the amount of fructan in the grain. 
     
     
         44 . A method for preparing a food or beverage, comprising mixing the barley grain of any one of  claims 1  to  15  or the barley wholemeal or flour of  claim 17  with another food or beverage ingredient. 
     
     
         45 . A method for providing starch, amylose, amylopectin, β-glucan, fructan, non-starch polysaccharide, dietary fibre or resistant starch to improve one or more indicators of health in a mammal, wherein the method comprises administering, to the mammal, a composition comprising barley grain, wholemeal or flour according to any one of  claims 1  to  17  or the food product according to any one of  claims 34  to  39 . 
     
     
         46 . The method of  claim 45  wherein the grain, flour, starch, amylose, amylopectin, β-glucan, fructan, non-starch polysaccharide, dietary fibre or resistant starch is in the form of a food product, a beverage or a pharmaceutical composition. 
     
     
         47 . The method of  claim 45  or  46 , wherein the one or more indicators of health is an increased number of beneficial intestinal bacteria, reduced number of aberrant crypt foci, increased mineral absorption, reduced level of insulin, reduced glycaemic index, reduced glycaemic load, reduced blood glucose, reduced blood pressure, reduced body weight, reduced blood cholesterol level, increased HDL cholesterol level, increased bone density, increased calcium levels, more frequent bowel movement, or improved blood serum cardiovascular profile. 
     
     
         48 . A method for ameliorating one or more symptoms of a condition associated with low levels of dietary starch, starch content, amylose, amylopectin, β-glucan, fructan, non-starch polysaccharide, dietary fibre or resistant starch in a subject, said method comprising administering orally to the subject grain according to any one of  claims 1  to  17  or a processed product comprising the starch, starch content, amylose, amylopectin, β-glucan, fructan, non-starch polysaccharide, dietary fibre or resistant starch obtained therefrom for a time and under conditions sufficient to ameliorate one or more symptoms. 
     
     
         49 . The method of  claim 48  wherein the condition is selected from the group consisting of diabetes, obesity, heart disease, hypertension, constipation, osteoporesis and cancer. 
     
     
         50 . The method of  claim 48  wherein the subject is a human.