TABLE 2.

Study of functional foods in cereals and millets using biotechnological approaches.

S. No	Crop	Functional food	Gene(s)/QTL(s)	Methodology	References
1	Rice	β-carotene	Daffodil &crtI gene	Transgenic and expression studies	Beyer et al. (2002)
			GtHMG1, GZmPsy1 and GPaCrtI1 genes		Tian et al. (2019)
		Fe and Zn	Ferritin	Transgenic and interval mapping	Lucca et al., 2002; Vasconcelos et al., 2003; Zhang et al., 2014
			genes (OsMTP6, OsNAS3, OsMT2D, OsVIT1, and OsNRAMP7) and 7 QTLs for each Fe and Zn	GWAS	Descalsota et al. (2018)
			48 MQTLs and 8 genes related to grain Fe and Zn concentration	MQTL analysis	Raza et al. (2019)
		α-linolenic acid rich	chimeric gene consisting of a maize Ubi1-P-int and a soybean GmFAD3 cDNA	Transgenics	Anai et al. (2003)
		Astaxanthin	sZmPSY1, sPaCrtI, sCrBKT, and sHpBHY genes	Transgenics	Zhu et al. (2018)
		α-tocopherol	OsGGR2 gene	RNA interference	Kimura et al. (2018)
		Phytic acid	OsITP5/6K-1 gene	RNA interference	Karmakar et al. (2020)
		Resistant starch	sbe3-rs gene	MAS	Yang et al. (2020)
2	Wheat	Micronutrients and Vitamins	Gpc-B1 gene and DArT markers	MAS	Distelfield et al., 2006; Uauy et al., 2006
		Zn, Fe, Cu, Mn, Se rich	QTLs for Zn, Fe, Cu, Mn, Se	Interval mapping	Pu et al. (2014)
		Anthocyanins	Ba gene Pp3 and Pp-D1 genes	MAS	Gordeeva et al., 2019; Gordeeva et al., 2020
3	Wheat and Barley	PUFAs	Artificial D6-desaturase gene	Transgenics using the biolistic method	Čertík et al. (2013)
4	Sorghum	Lysine	BHL-9	Transgenics	Zhao et al. (2003)
		Protein	hl gene and P721 opaque gene	Mutation breeding and MAS	Axtell et al., 1979; Welch and Graham, 2004
		Vitamin A	Prolamin and lysine alpha-ketoglutarate reductase genes z	Transgenics	Lipkie et al. (2013)
		Fe and Zn	QTLs and candidate genes like CYP71B34, ZFP 8	QTL mapping	Kotla et al. (2019)
		starch and amylose	Grain quality/starch pathway genes Sh2, Bt2, SssI, Ae1, and Wx	GWAS	De Alencar Figueiredo et al. (2010)
		Tannin antioxidant	tan-1, tan-1a and tan-1b	GWAS and expression analysis	Wu et al. (2012)
		β-carotene andZeaxanthin	3 QTLs for β carotene and 4 QTLs forZeaxanthin	GWAS	Cruet-Burgos et al. (2020)
5	Maize	Vitamin C and E rich	DHAR cDNA	Transgenics	Chen et al. (2003)
		pro-vitamin A	crtB and crtI	Transgenics	Aluru et al. (2008)
			lcyE	MAS	Yang et al. (2018)
			lcyE, crtRB1, and o2	MABB	Sagare et al. (2019)
		Fe and Zn	SNPs associated with kernel Fe and Zn content	GWAS and QTL mapping	Hindu et al. (2018)
6	Barley	Hordothionin rich	Hordothionin	Mutation breeding and MAS	Rao et al. (1994)
		β-glucan	Csl genes and QTLs	GWAS and paired-end-RNA sequencing-based transcriptome	Cai et al., 2013; Chen et al., 2014; Shu and Rasmussen 2014
		Malting protein	13–30 candidate genes like metallothionein, α-amylase, α-glucosidase, limit dextrinase, and β-ketoacyl synthase	cDNA array-based gene expression analysis and SAGE	White et al., 2006; Lapitan et al., 2009
		Palatable and easily digestible	starch branching enzymes SBEIIa and SBEIIb	RNAi technology	Regina et al. (2010)
		—	20 QTLs associated with TPC, FLC and AOA	GWAS	Han et al. (2018)
7	Oats	β-glucan	QTL’s for β-glucan	GWAS, MAS, QTL mapping	Gazal et al. (2014)
8	Pearl millet	Fe and Zn	QTLs (11 for Fe and 8 QTLs for Zn)	QTL mapping	Kumar et al. (2018)
9	Finger millet	Calcium	Calmodulin and Cax1 transporter genes	Differential expression/accumulation	Kumar et al. (2014)
10	Foxtail millet (Setaria italica)	storage associated genes	storage associated genes and noncoding RNAs	Transcriptome analysis	Qi et al. (2013)