Morpho-physiological responses of iaa9 tomato mutants to different levels of PEG simulated drought stress

Abstract

Abstract. Suminar E, Budiarto R, Nuraini A, Mubarok S, Ezura H. 2022. Morpho-physiologicalresponsesof iaa9 tomato mutants to different levels of PEG simulated drought stress. Biodiversitas 23: 3115-3126.This study aimed to analyze the morphological and physiological responses of iaa9 mutants and its WT-MT to different levels of drought stress in in vitro growing medium. This study applied a completely randomized design with two factors, i.e., tomato genotypes and polyethylene glycol (PEG) - induced drought stress levels. The factor of varieties consisted of three levels, i.e., WT-MT as control (G1), iaa9-3(G2), and iaa9-5 (G3). The factor of PEG-induced drought stress also consisted of four levels, i.e., 0% PEG as control (PEG0), 5% PEG (PEG5), 10% PEG (PEG10), and 15% PEG (PEG15). The results observed 12 weeks after culture showed the variations of the morpho-physiological response of WT-MT and mutant genotypes to PEG-induced in vitro drought stress. The WT-MT showed a higher reduction in plantlet height, root number, and root length than mutants under severe drought conditions. The plantlet fresh and dry weight of iaa9-3and iaa9-5were higher than its WT-MT under no drought conditions. The total chlorophyll content of WT-MT was lower than iaa9-5due to the significant gain of chlorophyll-b on that mutant rather than its WT-MT. However, the analysis of principal components and correlation revealed the reduction of morphological size and leaf pigment content in response to drought stress, irrespective of genotype factor. These results suggest that in vitro selection techniques using PEG is useful for the initial screening of drought-tolerant tomato.

SlIAA9 Mutation Maintains Photosynthetic Capabilities under Heat-Stress Conditions

“…This is because auxin maintains ROS homeostasis within plant tissue, auxin mediates ROS imbalances caused by abiotic stresses within plant tissue by increasing redox enzyme synthesis, thus preventing tissue damage. Previous research has established a link between higher auxin levels within plant tissue and higher SOD, CAT, APX, Glutathione, and NADPC activities [ 13 , 20 , 21 , 22 , 23 , 24 , 25 ]. iaa9-3 and iaa9-5 were also known to have higher proline content under simulated drought stress [ 20 ].…”

“…Previous research has established a link between higher auxin levels within plant tissue and higher SOD, CAT, APX, Glutathione, and NADPC activities [ 13 , 20 , 21 , 22 , 23 , 24 , 25 ]. iaa9-3 and iaa9-5 were also known to have higher proline content under simulated drought stress [ 20 ]. The aforementioned antioxidants are important ROS scavenger enzymes [ 18 ].…”

“…This increase in auxin levels would then be followed by the increased synthesis of enzyme and non-enzyme antioxidants [ 19 ]. Interestingly, increased levels of auxin-induced by either exogenous auxin applications or auxin overexpression mutants have been linked with increased activities of enzyme and non-enzyme antioxidants such as NADPH-thioredoxin reductase (NTRC), ascorbate peroxidase (APX), glutathione reductase (GR), catalase (CAT), superoxide dismutase (SOD), quinine reductase, peroxide dismutase, and proline [ 13 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ].…”

Comparative and Correlation Analysis of Young and Mature Kaffir Lime (Citrus hystrix DC) Leaf Characteristics

“…Correlation analysis is a statistical tool to find the strength and direction of relationships among several variables data. Numerous studies have used this tool to reveal the relationship among morphological, ecophysiological, and phytochemical variables of plant [7,8,14,75,76]. The present study used Pearson correlation analysis to reveal the strong, significant, and positive correlation between the photosynthetic rate and all leaf pigment variables, except anthocyanin [Table 1].…”

Parthenocarpic tomato mutants, iaa9-3 and iaa9-5, show plant adaptability and fruiting ability under heat-stress conditions

“…Parthenocarpic mutants, such as iaa9-3 and iaa9-5, can produce fruits under heat-stress conditions and help maintain stable tomato production in the future. Those two mutants also can growth under drought stress (Suminar et al, 2022). However, the ability of such mutants for plant growth and development, especially in the fruit set under heat-stress conditions, should be carefully evaluated.…”