Combined Application of Biostimulants and EDTA Improved Wheat Productivity under Cadmium Stress

Wheat(Triticum aestivum L.)exhibits a greater capacity for cadmium(Cd)absorption compared to other cereal crops,leading to elevated daily Cd intake,and posing a significant threat to public health.For the mitigation of Cd stress in sustainable and environmentally friendly way,a pot study was designed by using exogenous application of various biostimulants,i.e.,Nigella sativa and Ocimum sanctum extracts:0%,10%,and 20%in combination with the chelating agent ethylenediaminetetraacetic acid(EDTA)using 0 and 5 mg kg^(-1) under various levels of Cd stress(i.e.,0,5,10,and 15 mg kg^(-1) soil).Results revealed that Cd stress significantly reduced the seed emergence,growth,root,and allometric characters and yield-related parameters of wheat crops.The most observable reduc-tion was documented in wheat plants exposed to a higher Cd concentration(15 mg kg^(-1)),followed by the lower Cd level(control).The combined application of bio-stimulants and EDTA minimized the negative impacts of Cd stress.The highest increase in seedling emergence(5.44%),leaf area(50.60%),number of tillers(31.02%),grain yield per plant(24.28%),biological yield(13.97%),and decrease in Cd levels in grains(40%)was noticed where 20%foliar application of N.sativa and 10%of O.sanctum biostimulants were done using 5 mg kg^(-1) of soil-applied EDTA.This intervention demonstrated a notable reduction in Cd-induced negative effects,highlighting the potential of these substances in promoting sustainable wheat cultivation in contaminated environments.Moreover,it is an eco-friendly and approachable method at thefield level able to ensure food safety.

Increased resistance of drought by Trichoderma harzianum fungal treatment correlates with increased secondary metabolites and proline content

Plant secondary metabolites play vital role in plant stress response. In this study we investigated whether root colonization of tomato （Solanum lycopersicum） infected by Trichoderma harzianum leads to alterations in the biosynthesis of secondary plant metabolites including phytohormones and osmolyte proline under drought stress. Exposure of tomato to drought caused a drastic decline in plant growth and physiological parameters. Tomato inoculated with T. harzianum showed increased root and shoot growth and chlorophyll pigments as compared to uninoculated controls as well as drought stressed plants. Proline and total soluble protein content was increased in plants inoculated with T. harzianum under both normal as well as drought conditions. An obvious increase in phenol and flavonoid content was observed due to T. haczianum. In addition, T. hat-zianum inoculated plants maintained higher levels of growth regulators indole acetic acid, indole butyric acid, and gibberellic acid under drought stress. Improved secondary metabolites which play an important role in plant stress tolerance by T. hat-zianum may have coordinately worked for bringing the growth regulation by protecting membranes from reactive oxygen species （ROS） and enhance plant growth through accessing more nutrients by root system.

Identification of PtGai(a DELLA protein)in trifoliate orange and expression patterns in response to drought stress

Gibberellins(GAs)are an important hormone in regulating plant growth and development,and DELLA protein is an essential negative regulator of GA signal transduction.The aim of the study was to clone a GAinhibiting protein DELLA from trifoliate orange(Poncirus trifoliata L.Raf.)and to analyze the bioinformations and expression patterns of the protein gene in tissues and in response to drought stress.A DELLA protein was isolated from trifoliate orange and named as PtGai(Genebank number:MZ170959).The PtGai protein had 1731 bp open reading frames,along with 576 amino acid codes,and also grouped with sweet orange(XM_006430552.4).The PtGai protein sequence was 65%homology with the sequences of DELLA proteins in other plant families.PtGai protein existed in the nucleus based on the prediction of subcellular localization.PtGai protein could be expressed in roots,stems,and leaves,along with the highest expression in stems.PtGai was upregulated by drought stress in leaves and roots,along with the decrease of root total GA concentration and the inhibition of shoot and root biomass production.It indicated the characteristics of PtGai protein and the roles of PtGai in GA synthesis and plant growth.