Biochar and Seed Priming Technique with Gallic Acid: An Approach toward Improving Morpho-Anatomical and Physiological Features of Solanum melongena L. under Induced NaCl and Boron Stresses

Shumaila; Sami Ullah; Wadood Shah; Aqsa Hafeez; Baber Ali; Shahid Khan; Sezai Ercisli; Abdullah Ahmed Al-Ghamdi; Mohamed S Elshikh

doi:10.1021/acsomega.3c01720

Biochar and Seed Priming Technique with Gallic Acid: An Approach toward Improving Morpho-Anatomical and Physiological Features of Solanum melongena L. under Induced NaCl and Boron Stresses

ACS Omega. 2023 Jul 26;8(31):28207-28232. doi: 10.1021/acsomega.3c01720. eCollection 2023 Aug 8.

Authors

Shumaila¹, Sami Ullah¹, Wadood Shah², Aqsa Hafeez³, Baber Ali³, Shahid Khan⁴, Sezai Ercisli^{5

6}, Abdullah Ahmed Al-Ghamdi⁷, Mohamed S Elshikh⁷

Affiliations

¹ Department of Botany, University of Peshawar, Peshawar 25120, Pakistan.
² Biological Sciences Research Division, Pakistan Forest Institute, Peshawar 25120, Pakistan.
³ Department of Plant Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan.
⁴ Crops, Environment and Land Use Programme, Crop Science Department, Teagasc, Carlow R93 XE12, Ireland.
⁵ Department of Horticulture, Agricultural Faculty, Ataturk Universitesi, 25240 Erzurum, Turkey.
⁶ HGF Agro, Ata Teknokent, 25240 Erzurum, Turkey.
⁷ Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.

Abstract

Dynamic shifts in climatic patterns increase soil salinity and boron levels, which are the major abiotic factors that affect plant growth and secondary metabolism. The present study assessed the role of growth regulators, including biochar (5 g kg^-1) and gallic acid (GA, 2 mM), in altering leaf morpho-anatomical and physiological responses of Solanum melongena L. exposed to boron (25 mg kg^-1) and salinity stresses (150 mM NaCl). These growth regulators enhanced leaf fresh weight (LFW) (70%), leaf dry weight (LDW) (20%), leaf area (LA), leaf area index (LAI) (85%), leaf moisture content (LMC) (98%), and relative water content (RWC) (115%) under salinity and boron stresses. Physiological attributes were analyzed to determine the stress levels and antioxidant protection. Photosynthetic pigments were negatively affected by salinity and boron stresses along with a nonsignificant reduction in trehalose, GA, osmoprotectant, and catalase (CAT) and ascorbate peroxidase (APX) activity. These parameters were improved by biochar application to soil and presoaking seeds in GA (p < 0.05) in both varieties of S. melongena L. Scanning electron microscopy (SEM) and light microscopy revealed that application of biochar and GA improved the stomatal regulation, trichome density, epidermal vigor, stomata size (SS) (13 381 μm), stomata index (SI) (354 mm²), upper epidermis thickness (UET) (123 μm), lower epidermis thickness (LET) (153 μm), cuticle thickness (CT) (11.4 μm), trichome density (TD) (23 per mm²), vein islet number (VIN) (14 per mm²), vein termination number (VTN) (19 per mm²), midrib thickness (MT) (5546 μm), and TD (27.4 mm²) under salinity and boron stresses. These results indicate that the use of inexpensive and easily available biochar and seed priming with GA can improve morpho-anatomical and physiological responses of S. melongena L. under oxidative stress conditions.