Drought stress, as one of the most common environmental factors, seriously affects seed- ling establishment as well as plant growth and productivity. The growth of Toona ciliata is constrained by soil moisture deficit, and drought stress can reduce its productivity and limit its suitable growing environment. To explore the molecular mechanism of Toona ciliata responding to drought stress, leaves of two-year-old Toona ciliata seedlings were used as experimental materials for transcriptome sequencing and physiological index measurements. Under drought stress, the contents of Chl, MDA, POD, SP, SS, and RWC all change differently. We performed transcriptome sequencing, obtaining 4830 differential genes. The enrichment analysis indicates that the primary effects on the leaves of Toona ciliata under drought stress are related to photosynthesis and responses to plant hormone signal transduction. Transcription factor families associated with drought resistance include the NAC, WRKY, bZIP, bHLH, AP2-EREBP, C3H, GRAS, and FRAI transcription factor families. A weighted gene co-expression network analysis (WGCNA) analysis successfully identified 10 hub genes in response to drought stress in Toona ciliata leaves. Real-time quantitative PCR (RT-qPCR) validated the reliability of the transcriptomic data, and the analysis of its results showed a close correlation with the data obtained from RNA-seq. This study clarifies the transcriptional response of Toona ciliata to drought stress, contributing to the revelation of the molecular mechanisms of drought adaptation.

Line structured light vision sensor (LSLVS) calibration is to establish the location relationship between the camera and the light plane projector. This paper proposes a geometrical calibration method of LSLVS based on the property of vanish points and lines, by randomly moving the planar target. This method contains two steps, (1) the vanish point of the light stripe projected by the light plane is found in each target image, and all the obtained vanish points form the vanish line of the light plane, which is helpful to determine the normal of the light plane. (2) one 3D feature point on the light plane is acquired (one is enough, surely can be more than one) to determine d parameter of the light plane. Then the equation of the light plane under the camera coordinate system can be solved out. Computer simulations and real experiments have been carried out to validate our method, and the result of the real calibration reaches the accuracy of 0.141mm within the view field of about 300mm×200mm.

Sapindus delavayi is a drought-resistant tree species endemic to the dry–hot valleys of Southwestern China and is of great significance for soil and water conservation and ecological restoration. In this study, we sequenced the transcriptome of its leaves using the Illumina HiSeq 4000 platform and obtained 96.12 Gb of high-quality data (Q20 = 98.68%, Q30 = 95.62%), which were de novo assembled to obtain 89,228 unigenes (N50 = 1538 bp), of which 63,005 (70.61%) were successfully annotated to at least one database (NR, NT, SwissProt, KOG, KEGG, GO, Pfam). Overall, 53.96% of the unigenes in the S. delavayi leaves were annotated to Acer yangbiense, which belongs to the same family as S. delavayi. A total of 42,870 CDSs and 21,488 SSR loci were detected, with the highest mononucleotide repeat rate at 42.72% of the total number. Drought stress experiments identified 669–1203 differentially expressed genes (DEGs). Through our research, the first high-quality transcriptome database of S. delavayi has been constructed and its drought-resistance-related gene features have been analyzed, laying an important foundation for future functional gene mining, molecular marker development, molecular diversity studies, molecular breeding, and ecological adaptation research.