Three Crucial Pulses: ABA-Induced Alterations to Their Pigment Contents, Photosynthetic Gas Exchange Properties, Leaf Area, and Dry Matter Accumulation

Abstract

An experiment was conducted at TNAU, Coimbatore, to study the reaction of three significant pulses—Soyabean, greengram, and blackgram—to ABA that was sprayed from outside the plant. Pulse responses to drought stress demonstrate that chemical signals control stomatal aperture and photosynthesis. The exact mechanism by which Abscisic acid (ABA) chemical signals regulate the stomatal opening remains unknown, nevertheless. Thus, the purpose of this study was to determine the gas exchange parameter changes caused by ABA in the dominant soybean, green gram, and black gram varieties, and to find the crops that can improve water use efficiency by ABA treatments that maintain higher photosynthetic rates and lower transpiration rates. We grew all of the pulses in well-watered soil and gave them an ABA treatment. After the 22nd day after sowing, gas exchange metrics exhibited substantial alterations when an exogenous 10-5M ABA solution was applied for three consecutive days. Photosynthesis, leaf area, total dimethyl phosphorus, and photosynthetic pigments exhibited remarkable stability in greengram when treated with ABA sprays, although stomatal conductance decreased in all pulses. The transpiration rate was low in greengram compared to its control, while it was high in soyabean and blackgram. Clearly, under extended drought circumstances, ABA-induced increases in greengram represent an improvement in water-use efficiency. Pulses, ABA, stomatal conductance, transpiration, photosynthesis, pigment contents, leaf area, and total dry matter accumulation are all terms that fall under this umbrella.