Physiological and biochemical effect of 24-epibrassinoslide on cold tolerance in maize seedlings

Abstract

Germination and early seedling growth are important for establishment of maize because maize is chilling sensitive crop and low temperature during early period of growth can be detrimental to subsequent crop growth and productivity. Therefore, it is important to protect maize seedling from cold stress. A study was conducted on induced cold tolerance by 24-epibrassinoslide (EBR) at the Indian Agricultural Research Institute, New Delhi, India. Maize seedlings were raised in green house condition (25/18°C day-night temperatures). Ten days old seedlings were treated with EBR (0.0, 0.01, 0.1, 1.0 and 10 μM) and then divided into two sets, one set was kept in greenhouse (25/18°C day-night temperatures) and another was transferred to net house (cold stress). Data on various morpho-physiological traits was recorded after 7, 14 and 21 days of treatment. Exogenous application of 1.0 μM EBR had significant effect on growth and morpho-physiological traits under both conditions. The maize seedlings treated with EBR were more tolerant to cold stress than the untreated one. Significant increase in plant height, dry matter accumulation, chlorophyll content, total soluble proteins and starch contents was observed under both conditions, however, the results were more pronounced under cold stress. 1.0 μM concentration being the most effective under both conditions. Maintenance of high tissue water content, reduced membrane injury index, increased total chlorophyll, soluble sugar and protein content were taken as the possible indicators of EBR induced chilling tolerance.

Exogenous Brassinolide Enhances the Growth and Cold Resistance of Maize (Zea mays L.) Seedlings under Chilling Stress

“…Among the treatments, T2 had the best effect, and there were differences between the different varieties, with various degrees of cold resistance. This is similar to previous studies [59,62]. In this study, it was found that the photosynthesis-related indicators of the maize variety with stronger cold resistance were less changed.…”

“…Xu [58] and others have shown that BL can effectively alleviate the decrease in cucumber biomass caused by low temperature and can enhance the ability to resist chilling stress, by regulating the physiological metabolism of cucumber, thereby promoting the accumulation of dry matter [59]. The same conclusions have been corroborated in crops such as maize, rice and wheat [11,[60][61][62]. Within the experimental range, the foliar spraying of three concentrations (T1, T2, T3) of BL solution significantly reduced the inhibitory effects maize seedlings caused by low temperature, and the T2 treatment effect was the most significant.…”

Brassinosteroid and gibberellin control of plant height in maize (Zea mays. L)

“…In this study, we focused on BR and GA control of seedling traits, as BR and GA promote seedling vigor and growth (Fuchs and Lieberman, 1968;Evans and Poethig, 1995;Clouse, 2001;Özdemir et al, 2004;Ashraf et al, 2010) and they are positively correlated to seedling stress tolerance of drought, salinity, cold/heat, and heavy metals in different plant species such as maize, sorghum, Arabidopsis and rice (Anuradha and Rao, 2001;Vardhini and Rao, 2003;Kagale et al, 2007;Colebrook et al, 2014). For example, exogenous application of BRs increased the cold tolerance of maize seedlings (Singh et al, 2012), and increased endogenous levels of GAs were effective in protecting maize seedlings from drought stress For both DHB47 and DHZ51, shoot length, mesocotyl length, and primary root length were reduced with the application of BR and GA inhibitors compared to water treatment. BRM, BRS, GAM and GAS was below 1.0 for all the 207 BGEM lines except for one line BGEM-0123-N with BRS equal to 1.1.…”

Maize seedling morphology and defence hormone profiles, but not herbivory tolerance, were mediated by domestication and modern breeding

“…Both dry and wet weights for seedling roots and shoots were measured because while both are indices of size, wet weight additionally reflects tissue water content, which is generally relevant to seedling health and performance (e.g. Ping et al ., ; Zygielbaum et al ., ; Singh et al ., ). A total of 34 Balsas teosinte seedling pairs (Guachinango = 13, San Lorenzo = 11 and El Cuyotomate = 10), 47 landrace maize pairs (Tuxpeño = 16, Tepecintle = 15 and Olotón = 16 ) and 44 maize inbred line pairs (B73 = 16, CML176 = 15 and MP708 = 13 ) were evaluated as described above.…”