The common walnut (Juglans regia L.) and iron walnut (J. sigillata Dode) are well-known economically important species cultivated for their edible nuts, high-quality wood, and medicinal properties and display a sympatric distribution in southwestern China. However, detailed research on the genetic diversity and introgression of these two closely related walnut species, especially in southwestern China, are lacking. In this study, we analyzed a total of 506 individuals from 28 populations of J. regia and J. sigillata using 25 EST-SSR markers to determine if their gene introgression was related to sympatric distribution. In addition, we compared the genetic diversity estimates between them. Our results indicated that all J. regia populations possess slightly higher genetic diversity than J. sigillata populations. The Geostatistical IDW technique (H_O, PPL, N_A and PrA) revealed that northern Yunnan and Guizhou provinces had high genetic diversity for J. regia while the northwestern Yunnan province had high genetic diversity for J. sigillata. AMOVA analysis revealed that significant genetic variation was mainly distributed within population as 73% in J. regia and 76% in J. sigillata. The genetic differentiation (F_ST) was 0.307 between the two walnut species (p < 0.0001), which was higher than F_ST values within populations (J. regia F_ST = 0.265 and J. sigillata F_ST = 0.236). However, the STRUCTURE analysis of the J. regia and J. sigillata populations revealed two genetic clusters in which gene introgression exists, therefore, the boundary of separation between these two walnut species is not clear. Moreover, these results were validated by NJ and UPGMA analysis with additional conformation from the PCoA. Based on the SSR data, our results indicate that J. sigillata is an ecotype of J. regia. Taken together, these results reveal novel information on population genetics and provide specific geographical regions containing high genetic diversity of the Juglans species sampled, which will assist in future conservation management.

Cyclic nucleotide gated ion channels (CNGCs) in plants have very important role in signaling and development. The study reports role of CNGC19 and CNGC20 in salt stress in A. thaliana. In-silico, genome wide analysis showed that CNGC19 and CNGC20 are related to salt stress with maximum expression after 6 h in A. thaliana. The position of inserted T-DNA was determined (in-vivo) through TAIL-PCR for activation tagged mutants of CNGC19 and CNGC20 under salt stress. The expression of AtCNGC19 and AtCNGC20 after cloning under 35S promoter of expression vectors pBCH1 and pEarleyGate100 was determined in A. thaliana by real-time PCR analysis. Genome wide analysis showed that AtCNGC11 had lowest and AtCNGC20 highest molecular weight as well as number of amino acid residues. In-vivo expression of AtCNGC19 and AtCNGC20 was enhanced through T-DNA insertion and 35S promoter in over-expressed plants under high salt concentration. AtCNGC19 was activated twice in control and about five times under 150 mM NaCl stress level, and expression value was also higher than AtCNGC20. Phenotypically, over-expressed plants and calli were healthier while knock-out plants and calli showed retarded growth under salinity stress. The study provides new insight for the role of AtCNGC19 and AtCNGC20 under salt stress regulation in A. thaliana and will be helpful for improvement of crop plants for salt stress to combat food shortage and security.

Castanea henryi is Pearl chestnut, or the willow-leaved chestnut, which is widely distributed in the warm temperate subtropical climates of China. We determined the complete chloroplast genome sequence for C. henryi using Illumina sequencing data. The complete chloroplast sequence is 160,907 bp in length and contains a pair of 25,689 bp inverted repeats (IRs), a large single-copy (LSC) region of 90,531 bp, and a small single-copy (SSC) region of 18,998 bp. It contains 132 genes, including 102 protein-coding genes, eight ribosomal RNA genes (four RNA species), 46 transfer RNA genes, and two pseudogenes (ycf1 and ndhK). The overall GC content of the whole genome is 36.7%. Phylogenetic analysis based on 21 chloroplast genomes indicates that C. henryi is closely related to Chinese chestnut (C. mollissima) in Fagaceae.

Epigenetics mechanisms, such as histone alterations, DNA methylation, and small non-coding RNAs, play a vital role in regulating plant drought tolerance by modulating gene expression. These changes enable plants to conserve water, protect cells, and recover from stress. Epigenetic memory also helps plants respond more effectively to recurring droughts. Understanding these mechanisms offers promising approaches for improving crop flexibility by breeding and biotechnology, crucial for addressing climate change and water scarcity challenges in agriculture.