Chromosome doubling mediates superior drought tolerance in Lycium ruthenicum via abscisic acid signaling

Plants are continuously affected by unfavorable external stimuli,which influences their productivity and growth.Differences in gene composition and expression patterns lead homologous polyploid plants to exhibit different physiological phenomena,among which enhanced environmental adaptability is a powerful phenotype conferred by polyploidization.The mechanisms underlying the differences in stress tolerance between diploids and autotetraploids at the molecular level remain unclear.In this research,a full-length transcription profile obtained via the singlemolecule real-time(SMRT)sequencing of high-quality single RNA molecules for use as background was combined with next-generation transcriptome and proteome technologies to probe the variation in the molecular mechanisms of autotetraploids.Tetraploids exhibited an increase in ABA content of 78.4%under natural conditions and a superior stress-resistance phenotype under severe drought stress compared with diploids.The substantial differences in the transcriptome profiles observed between diploids and autotetraploids under normal growth conditions were mainly related to ABA biosynthesis and signal transduction pathways,and 9-cis-epoxycarotenoid dioxygenase 1(NCED1)and NCED2,which encode key synthetic enzymes,were significantly upregulated.The increased expression of the ABREbinding factor 5-like(ABF5-like)gene was a pivotal factor in promoting the activation of the ABA signaling pathway and downstream target genes.In addition,ABA strongly induced the expression of osmotic proteins to increase the stress tolerance of the plants at the translational level.We consider the intrinsic mechanisms by which ABA affects drought resistance in tetraploids and diploids to understand the physiological and molecular mechanisms that enhance abiotic stress tolerance in polyploid plants.

A New Image Segmentation Method Based on Fractional-Varying-Order Differential

In order to solve the problem of image segmentation with intensity inhomogeneity,a new partial differential equation image segmentation model based on fractional-varying-order differen-tial is proposed.This model introduces an adaptive coefficient to set disparate differential order in-tervals for pixel with different gray values and use fractional-varying-order differential to process the input image combined with the CV model,then use a variety of image segmentation evaluation indicators,such as true positive(TP)rate,false positive(FP)rate,precision(P),Jaccard similar-ity(JS)rate,and Dice coefficient(DC)rate to measure the pros and cons of our model.The ex-perimental results show that our method is improved on the original basis,which is more condu-cive to us to obtain more image details and obtain better segmentation results.

The coloring mechanism of a novel golden variety in Populus deltoides based on the RGB color mode

Compared to flower color and red leaf mutants,the mechanism of yellow leaf formation in woody plants is more complicated and less understood.Poplars are common and widely distributed perennial trees.Here,we obtained a golden leaf mutant poplar variety(JHY)and compared it with its original green leaf poplar(Populus sp.Linn.‘2025’)in terms of phenotype,pigment content,the transcriptomes and metabolomes.Through transcriptome sequencing,we found that the chlorophyll degradation genes,and the genes in anthocyanin metabolism in JHY were up-regulated compared to L2025 and the carotenoid synthesis genes were down-regulated.Further based on HPLC-ESI-MS/MS technology,16 differentially expressed anthocyanins were identified,14 reddish anthocyanins of which were significantly up-regulated.According to these results,we proposed a coloring mechanism of JHY based on the RGB color mode.The yellow color of carotenoids and the red color of anthocyanins overlay each other,combined with a reduction in chlorophyll,turning the leaves golden.This study systematic analyzes the causes of golden leaf formation through the omics integration approach,which will provide reference for the breeding of golden leaf trees.