Table 1.

Components of coping strategies and agricultural resistance in crops and model plants.

Plant Species/Genotypes	Stress Imposition Stress Level	Components of Coping Strategy	Agricultural Resistance	References
Arabidopsis thaliana transgenic line RCAR10-4	soil pot experiment water withholding 8 weeks severe stress RWC—not performed	increased expression of ABA receptor reduced stomatal conductance with maintenance of carbon assimilation	improvement in WUE and growth	[93]
tomato transgenic line sp12	soil pot experiment water withholding at four- or five-leaf stage 5 days RWC—not performed	overexpression of ABA biosynthesis of gene (NCED) increased ABA level in root and leaves reduced stomatal conductance increased root hydraulic conductivity, water status improvement	improvement in WUE without trade-offs in carbon assimilation	[38]
wheat ‘Luhan7′	soil pot experiment, irrigation withheld at tillering and jointing stage 10 days moderate stress RWC 85–89%	osmotic adjustment (proline, sugars) stomata closure activation of antioxidant system	high photosynthetic CO2 fixation high drought index and harvest index	[97]
barley H. vulgare ‘Martin’ H. spontaneum HS41-1	soil pot experiment, water withholding at flowering stage 13 days severe stress RWC—not performed	high expression of signal transduction genes (TFs, CDPK, membrane binding proteins) and functional genes directly involved in coping strategy (stomatal behavior, synthesis of glycine-betaine, proline, antioxidants, dehydrins)	higher chlorophyll content and lower grain yield losses than in genotype without enhanced expression of coping strategy genes	[82]
barley ‘Yousof’ and ‘Morocco’	soil pot experiment water withholding at two weeks seedling stress duration? mild stress RWC ~88%	high level of dehydrin and alpha-tocopherol involved in PSII protection in ‘Yousof’	lower reduction in CO2 assimilation rate and performance index in ‘Yousof’	[98]
transgenic rice	soil pot experiment water withholding at pre-anthesis and post-anthesis 6–10 days mild stress RWC ~85%	increased CK synthesis, increased expression of BR related genes and repression of JA-related genes modification of source/sink relationships, a stronger sink capacity	higher grain yield with improved quality (nutrients and starch content)	[107]
wheat ‘Zagros’ and ‘Marvdaht’	soil pot experiment soil moisture at about 50% of field capacity 31 days RWC—not performed	higher ABA and proline accumulation in ‘Zagros’ than ‘Marvdaht’	higher harvest index and lower grain yield reduction in ‘Zagros’ than ‘Marvdaht’	[101]
barley introgression lines with wild allele p5cs1- S42IL-141, S42IL-141	soil pot experiment reduction in irrigation at booting stage mild stress 15-day RWC ~83%	significantly higher spike and leaf proline level than other line	maintenance of high photosynthetic rate and inherent WUE, high final seed productivity	[102]
barley near-isogenic line with wild allele P5cs1- NIL 143	rhizoboxes filled with soil soil water content decreased from 40% at the beginning to 6% after 17 days (three-leaf seedling) severe stress RWC ~59%	higher root and shoot proline content than in other genotypes, less severe drought symptoms, better stomatal conductance, higher RWC, enhanced root growth	enhanced net assimilation rate	[103]
quinoa ‘Titicaca’	field experiment soil pot experiment mild to severe RWC—not performed	ABA increase, high WUE	no yield reduction	[84,87]
quinoa 10 varieties	field experiment RWC—not performed	high carbon isotope discrimination	high yield	[96]
wheat drought-tolerant ‘Halberd’ drought-sensitive ‘Cranbrook’	soil pot experiment growth chamber water withholding drought stress at the young microspore stage RWC—not performed	ABA increase, stomatal closure at the start of stress, inhibition of photosynthesis in ‘Halberd’ delayed stomatal closure and activation of defense response repression of ABA synthesis enrichment of genes involved in AUX, CK and ET metabolism/signaling in ‘Cranbrook’	lower yield reduction in ‘Cranbrook’	[105]
transgenic Oryza sativa cotton	soil pot experiment in greenhouse and growth chamber irrigation reduction RWC—not performed	increased CK level modifications of source/sink relationships delayed senescence increased expression of BR-related genes	improved grain yield and grain quality improved photosynthesis, biomass accumulation	[106,107]