Amount of digalactosyldiacylglycerol (DGDG) in wheat leaves (normalized mass spectral signal per dry leaf mass) over time. One-month-old plants were inoculated or left noninoculated at day 0. Abbreviations are: R- = average of three resistant wheat cultivars (Betty, Jagger, Karl 92) without inoculation; S- = average of three susceptible cultivars (Larned, Newton, TAM 105) without inoculation; R+ = resistant cultivars with inoculation; and S+ = susceptible cultivars with inoculation. Each data point is the mean of three cultivars each with five replications. Equations for the trend lines and P values for significance of the slopes different from zero are as follows: R- , Y = -1.25 X + 61.02 (P = 0.0367); S-, Y = -1.01 X + 54.95 (P = 0.0965); R+, Y = -1.70 X + 57.96 (P = 0.0047); and S+, Y = -5.02 X + 58.85 (P = <0.0001).