Integrated Analysis of Osmotic Stress and Infrared Thermal Imaging for the Selection of Resilient Rice Under Water Scarcity

Abstract

The climate change scenario has increased the severity and frequency of drought stress, which limits the growth and yield of rice worldwide. There is a dire need to select drought-tolerant rice varieties to sustain crop production under water scarcity. Therefore, the present study effectively combined morpho-physiological and biochemical approaches with the technology of infrared thermal imaging (IRTI) for a reliable selection of drought-tolerant genotypes. Initially, we studied 28 rice genotypes including 26 advance lines and three varieties for water stress tolerance under net house conditions. Three genotypes NIBGE-DT-02, KSK-133, and NIBGE-DT-11 were selected based on the Standard Evaluation System (SES) scoring for drought tolerance. NIBGE-DT-02 showed tolerance to polyethylene glycol (20%) induced osmotic stress indicated by a minimum reduction in seedling length, biomass, chlorophyll content, and increased leaf proline content as compared to susceptible varieties under a hydroponic system. NIBGE-DT-02 was further evaluated for water withholding at varying growth stages, i.e., 30 and 60 days after transplantation (DAT) in pots under net house conditions. NIBGE-DT-02 showed a significantly lower reduction (35.9%) in yield as compared to a susceptible variety (78.06%) under water stress at 60 DAT with concomitant induction of antioxidant enzymes such as peroxidase, catalase, and polyphenol oxidase. A significant increase (45.9%) in proline content, a low increase (7.5%) in plant temperature, along with a low reduction in relative water content (RWC) (5.5%), and membrane stability index (MSI) (9%) were observed under water stress at 60 DAT as compared to the well-watered control. Pearson correlation analysis showed the strong correlation of shoot length with MSI and root length with RWC in rice genotypes at the later growth stage. Furthermore, Regression analysis indicated a negative correlation between plant temperature of NIBGE-DT-02 and proline, RWC, MSI, and peroxidase enzyme under variable water stress conditions. All these responses collectively validated the adaptive response of selected genotypes under water stress during different growth stages. Tolerant genotypes can be used in breeding programs aimed at improving drought tolerance and can expand rice cultivation. Furthermore, this study provides a foundation for future research directed to utilize IRTI as a fast and non-destructive approach for the selection of potent rice genotypes better adapted to water scarcity from wide germplasm collection.

Mitigation of water scarcity with sustained growth of Rice by plant growth promoting bacteria

“…Seeds of drought-susceptible rice genotype Super Basmati (Variety 1; V1) ( Sabar and Arif, 2014 ; Mumtaz et al., 2019 ) and drought-tolerant rice genotypes NIBGE-DT02 (Variety 2; V2) and IR55419-04 (Variety 3; V3) ( Sabar et al., 2019 ) selected in our previous study ( Mahreen et al., 2022 ) were obtained from DNA Marker and Plant Genomics Lab of Agricultural Biotechnology Division (ABD), National Institute for Biotechnology and Genetic Engineering (NIBGE) Faisalabad.…”

“…Transplantation of 35-day-old rice seedlings was done in earthen pots. Recommended doses of essential nutrients P and N were applied as urea (CH 4 N 2 O) and diammonium phosphate, respectively, as described by Mahreen et al. (2022) .…”

“…Transplantation of 35-day-old rice seedlings was done in earthen pots. Recommended doses of essential nutrients P and N were applied as urea (CH 4 N 2 O) and diammonium phosphate, respectively, as described by Mahreen et al (2022). Control treatment pots were well-irrigated during the whole experiment, whereas stress-treated pots were well-irrigated at 30 days after transplantation (DAT) and then exposed to water withholding for the next 15 consecutive days.…”

“…After the plant's morpho-physiological analysis in response to bacterial inoculation under water stress, for biochemical analysis different antioxidant enzyme activities were studied. A homogenized leaf sample of 0.1 g was used for the determination of each enzyme analysis; the details were mentioned in our previous study (Mahreen et al, 2022). Peroxidase (POD) activity was measured using guaiacol (substrate) at 470 nm on a spectrophotometer (CamSpec M350, UV visible, UK) as described by Munawar et al (2021).…”

Rice Responses to Water Limiting Conditions: Improving Stress Management by Exploiting Genetics and Physiological Processes

“…Thermal imaging was recently applied to screen rice germplasm for tolerance to water stress [95]; the approach was applied at the seedling stage on 28 rice genotypes (26 advanced lines and one tolerant IR-55419-04, one susceptible Super Basmati variety) in order to integrate morphological, physiological, and biochemical approaches with improved in situ methods, i.e., infrared thermal imaging. The best indica genotype, identified as NIBGE-DT-02, showed significant production of osmoregulators such as proline, antioxidants, high relative water content, better yield, and tolerance to water stress irrespective of the evaluated growth stage, making it a useful genetic material for breeding programs aimed at increasing rice cultivation under water stress condition.…”