Photosynthetic Plasticity and Stomata Adjustment in Chromosome Segment Substitution Lines of Rice Cultivar KDML105 under Drought Stress

Abstract

The impact of increasing drought periods on crop yields as a result of global climate change is a major concern in modern agriculture. Thus, a greater understanding of crop physiological responses under drought stress can guide breeders to develop new cultivars with enhanced drought tolerance. In this study, selected chromosome segment substitution lines of KDML105 (KDML105-CSSL) were grown in the Plant Phenomics Center of Kasetsart University in Thailand under well-watered and drought-stressed conditions. Physiological traits were measured by observing gas exchange dynamics and using a high-throughput phenotyping platform. Furthermore, because of its impact on plant internal gas and water regulation, stomatal morphological trait variation was recorded. The results show that KDML105-CSS lines exhibited plasticity responses to enhance water-use efficiency which increased by 3.62%. Moreover, photosynthesis, stomatal conductance and transpiration decreased by approximately 40% and plant height was reduced by 17.69%. Stomatal density tended to decrease and was negatively correlated with stomatal size, and stomata on different sides of the leaves responded differently under drought stress. Under drought stress, top-performing KDML105-CSS lines with high net photosynthesis had shorter plant height and improved IWUE, as influenced by an increase in stomatal density on the upper leaf side and a decrease on the lower leaf side.

Potential breeding target genes for enhancing agronomic drought resistance: A yield‐survival balance perspective

“…Imaging‐based phenotyping systems, on the other hand, have the advantages of higher throughput and operational easiness (Fichtl et al, 2023). Several phenomics platforms have been deployed in agricultural practices (Dwivedi et al, 2021; Lertngim et al, 2022). For example, different sensing systems, including hyperspectral passive sensor, active flash sensor, the Crop Circle and GreenSeeker, were used to evaluate drought resistance among 20 wheat cultivars, where the most significant relationship was detected between Crop Circle and drought‐related parameters (Becker & Schmidhalter, 2017).…”

MicroRNA: A Dynamic Player from Signalling to Abiotic Tolerance in Plants

“…Stomata play a central role in the exchange of gases between plants and their environment, and stomata opening and closing are influenced by environmental signals, as well as being regulated by endogenous hormones, which in turn affects the plant's response and tolerance to drought stress. ABA is the most critical hormone in drought stress, regulating water loss and stomatal opening and closing [28][29][30][31]. MiR393 positively regulates stomatal density and negatively regulates guard cell length, while overexpressing lines have the opposite phenotype to the deletion mutant, possibly due to miR393 regulating the expression of ARF5 and two stomatal-development-related genes, EPF1 and SPCH.…”

The Role of MicroRNA in Plant Response to Abiotic Stress

“…Stomata play a central role in the exchange of gases between plants and their environment, and their opening and closing is influenced by environmental signals, as well as being regulated by endogenous hormones, which in turn affect the plant's response and tolerance to drought stress. ABA is the most critical hormone in drought stress, it regulating water loss, stomatal opening and closing [21][22][23][24]. MiR393 positively regulated stomatal density and negatively regulated guard cell length, while overexpressing plants had the opposite phenotype to the deletion mutant, possibly due to miR393 regulating the expression of growth hormone response factor 5 (ARF5) and three stomatal development-related genes, epidermal pattern factor 1 (EPF1), SPEECHLESS (SPCH) and MUTE.…”