Mutation of SlARC6 leads to tissue-specific defects in chloroplast development in tomato

The proliferation and development of chloroplasts are important for maintaining the normal chloroplast population in plant tissues.Most studies have focused on chloroplast maintenance in leaves.In this study,we identified a spontaneous mutation in a tomato mutant named suffulta(su),in which the stems appeared albinic while the leaves remained normal.Map-based cloning showed that Su encodes a DnaJ heat shock protein that is a homolog of the Arabidopsis gene AtARC6,which is involved in chloroplast division.Knockdown and knockout of SlARC6 in wild-type tomato inhibit chloroplast division,indicating the conserved function of SlARC6.In su mutants,most mesophyll cells contain only one or two giant chloroplasts,while no chloroplasts are visible in 60%of stem cells,resulting in the albinic phenotype.Compared with mature tissues,the meristem of su mutants suggested that chloroplasts could partially divide in meristematic cells,suggesting the existence of an alternative mechanism in those dividing cells.Interestingly,the adaxial petiole cells of su mutants contain more chloroplasts than the abaxial cells.In addition,prolonged lighting can partially rescue the albinic phenotypes in su mutants,implying that light may promote SlACR6-independent chloroplast development.Our results verify the role of SlACR6 in chloroplast division in tomato and uncover the tissue-specific regulation of chloroplast development.

Robust hydrogel sensors for unsupervised learning enabled sign-to-verbal translation

Highly stretchable and robust strain sensors are rapidly emerging as promising candidates for a diverse of wearable electronics.The main challenge for the practical application of wearable electronics is the energy consumption and device aging.Energy consumption mainly depends on the conductivity of the sensor,and it is a key factor in determining device aging.Here,we design a liq-uid metal(LM)-embedded hydrogel as a sensing material to overcome the bar-rier of energy consumption and device aging of wearable electronics.The sensing material simultaneously exhibits high conductivity(up to 22 S m�1),low elastic modulus(23 kPa),and ultrahigh stretchability(1500%)with excel-lent robustness(consistent performance against 12000 mechanical cycling).A motion monitoring system is composed of intrinsically soft LM-embedded hydrogel as sensing material,a microcontroller,signal-processing circuits,Bluetooth transceiver,and self-organizing map developed software for the visu-alization of multi-dimensional data.This system integrating multiple functions including signal conditioning,processing,and wireless transmission achieves monitor hand gesture as well as sign-to-verbal translation.This approach provides an ideal strategy for deaf-mute communicating with normal people and broadens the application of wearable electronics.