Gibberellic acid improves water deficit tolerance in maize plants

Abstract

Ab stractThe com bi na tion ef fects of wa ter stress and gibberellic acid (GA 3 ) on phys i o log i cal at trib utes and nu tri tional sta tus of maize (Zea mays L. cv., DK 647 F1 ) were stud ied in a pot exper i ment. Maize plants were grown in the con trol (well watered WW) and wa ter stress sub jected to treated both wa ter stress and two con cen tra tions of gibberellic acid (GA 3 25 mg·L -1 , 50 mg·L -1 ). WS was im posed by main tain ing the moisture level equiv a lent to 50 % pot ca pac ity whereas the WW pots were main tained at full pot ca pac ity. Wa ter stress re duced the to tal dry weight, chlo ro phyll con cen tra tion, and leaf rel ative wa ter con tent (RWC), but it in creased proline ac cu mu lation and elec tro lyte leak age in maize plants and ap pears to affect shoots more than roots. Both con cen tra tions of GA 3 (25 and 50 mg·L -1 ) largely en hanced the above phys i o log i cal param e ters to lev els sim i lar to con trol. WS re duced leaf Ca 2+ and K + con cen tra tions, but ex og e nous ap pli ca tion of GA 3 increased those nu tri ent lev els sim i lar or close to con trol. Ex og enous ap pli ca tion of GA 3 im proved the wa ter stress tol er ance in maize plants by main tain ing mem brane per me abil ity, en hancing chlo ro phyll con cen tra tion, leaf rel a tive wa ter con tent (LRWC) and some macro-nu tri ent con cen tra tions in leaves.List of abbreviations: GA 3 -Gibberellic acid; LRWC-Leaf rel a tive wa ter con tent; WW-Well wa tered; WS-wa ter stress In tro duc tionMaize is grown all over the world un der a wide range of cli mates. Drought is the main con straint for maize, caus ing se vere yield re duc tions (Maiti et al. 1996). Genotypic dif fer ences have been iden tified for a range of mor pho log i cal and phys i o log i cal char ac ter is tics (Ackerson 1983) as well as growth re sponses of maize to wa ter def i cit (O'Regan et al. 1993, Sinclair et al. 1990).Con trary to other fac tors that may limit crop yields (e.g. acid, al ka line or sa line soils) wa ter avail abil ity is highly vari able dur ing crop grow ing sea son and dif fers from year to year. As a con se quence, wa ter def i cit is an ubiq ui tous lim it ing fac tor in ag ri culture, es pe cially in semi-arid re gions (Gutier rez --Boem and Thomas 1999).The ef fects of wa ter def i cit on plant phys i ol ogy very de pends on the spe cies and de gree of tol erance. Gen er ally, drought quickly af fects the processes re lated to cell tur gid ity and par tic u larly the growth of the meristem (Figueiredo et al. 1999).In re la tion to en vi ron men tal ef fects, irradiance and low tem per a ture in duced changes in GA me tab olism were re viewed by Hedden (1999), but lit tle is known about changes in duced by wa ter stress (Pos -331 ACTA PHYSIOLOGIAE PLANTARUM

Exogenous Application of Gibberellic Acid Improves the Maize Crop Productivity Under Scarce and Sufficient Soil Moisture Condition

“…Various growth parameters, like LAI, LAD, NAR, and TDM, were reduced under drought stress and without growth enhancer. It has been previously reported that gibberellic acid is helpful in enhancing growth of wheat, maize, and tomato under water stress conditions (Kaya et al, 2006;Maggio et al, 2010). Improved growth might be due to optimum uptake of various nutrients, as gibberellic acid found to play an important role in enhancing the N, P, K, content (Soad, 2005;Sayed, 2001) (Fig.…”

Effects of ascorbic acid and gibberellin A3 on alleviation of salt stress in common bean (Phaseolus vulgaris L.) seedlings

“…AsA supplement, implying that this treatment can alleviate the deleterious effects of salt stress. Gibberellic acid has been reported to be helpful in enhancing growth of wheat, maize and tomato under saline conditions (Ashraf et al 2002;Kaya et al 2006;Maggio et al 2010). Salt stress was strong enough to inhibit plant growth due to reduction in gibberellin production (Kaya et al 2006).…”

“…Gibberellic acid has been reported to be helpful in enhancing growth of wheat, maize and tomato under saline conditions (Ashraf et al 2002;Kaya et al 2006;Maggio et al 2010). Salt stress was strong enough to inhibit plant growth due to reduction in gibberellin production (Kaya et al 2006). Table 5 Effects of sodium chloride, gibberellic acid and ascorbic acid on content of sodium in root (Na ROOT ) and shoot (Na SHOOT ), and potassium in root (K ROOT ) and shoot (K SHOOT ) in Phaseolus vulgaris L. Therefore, addition of exogenous gibberellic acid might increase seedling growth by enhancing the content of endogenous gibberellin as that mentioned by Rodriguez et al (2006).…”

Physiological aspects in cotton cultivars in response to application leaf gibberellic acid

“…Thus, the exogenous application of GA 3 as mitigating, has enabled the plants retain a larger amount of water in the leaves, favoring the growth process, mainly related to elongation and cell division, even under stress conditions (Kaya et al, 2006;Taiz and Zeiger, 2013). However, so that the plants can respond to the stimulus applying GA 3 , studies are needed to elucidate the application form and the correct dose of phytohormone for each species.…”