Brassinosteroids, which control plant growth and development, are sensed by the membrane receptor kinase BRASSINOSTEROID INSENSITIVE 1 (BRI1). Brassinosteroid binding to the BRI1 leucine-rich repeat (LRR) domain induces heteromerisation with a SOMATIC EMBRYOGENESIS RECEPTOR KINASE (SERK)-family co-receptor. This process allows the cytoplasmic kinase domains of BRI1 and SERK to interact, trans-phosphorylate and activate each other. Here we report crystal structures of the BRI1 kinase domain in its activated form and in complex with nucleotides. BRI1 has structural features reminiscent of both serine/threonine and tyrosine kinases, providing insight into the evolution of dual-specificity kinases in plants. Phosphorylation of Thr1039, Ser1042 and Ser1044 causes formation of a catalytically competent activation loop. Mapping previously identified serine/threonine and tyrosine phosphorylation sites onto the structure, we analyse their contribution to brassinosteroid signaling. The location of known genetic missense alleles provide detailed insight into the BRI1 kinase mechanism, while our analyses are inconsistent with a previously reported guanylate cyclase activity. We identify a protein interaction surface on the C-terminal lobe of the kinase and demonstrate that the isolated BRI1, SERK2 and SERK3 cytoplasmic segments form homodimers in solution and have a weak tendency to heteromerise. We propose a model in which heterodimerisation of the BRI1 and SERK ectodomains brings their cytoplasmic kinase domains in a catalytically competent arrangement, an interaction that can be modulated by the BRI1 inhibitor protein BKI1.
Superabsorbent polymers (SAPs) can improve water use efficiency in agriculture.
According to their source, SAPs can be classified as natural and synthetic polymers.
Representative achievements in the design and modification of SAPs are introduced.
Future trends and rational design for SAPs with desired properties are concluded.
Recent developments in small scale agriculture call for minimum soil disturbance in crop production but crop varieties specific to conservation tillage are needed to be used by farmers. A field experiment was conducted at three selected districts of southern nation’s nationalities and people’s region during 2017and 2018 cropping seasons to evaluate the growth and grain yield response of maize varieties to conservation tillage (minimum soil disturbance, residue retention, and herbicide application). The experiment was laid out in randomized complete block design consisting of five varieties (016K-SPRH, 016k-SBRH, BH-540, BH-546, and BH-547) within three replications. Pre planting herbicide (roundup) sprayed to control pre emerged weeds. Growth and yield parameters of maize were measured. Combined analysis of variance over 2017 and 2018 across locations revealed that the maize BH-546 and BH-547 had higher grain yield (5.2 and 5.0 t ha-1), but not significantly higher than the BH 540 (4.9 t ha-1). Although the varieties 016K-SPRB and 016k-SBRH gave lower yield than the hybrids, their performance in growth across locations over years was attractive. The highest plant height (208cm), ear height (108cm) with statistically similar above ground biomass of the varieties to that of the hybrids indicated the potential of materials for further research. Moreover, these varieties performed significantly adaptive and meaningful growth and yield indicating conservation tillage cannot affect the performance of maize growth and yield across locations over years.
This paper reviews this state of the art in measuring plant signaling, using principles and tools borrowed from and inspired by engineering, as well as efforts to use this knowledge to enable rapid, rational re-engineering of plant development.
Sensitive, genetically encoded reporters (biosensors), in combination with emerging single-cell transcriptomics approaches, are providing increasingly detailed molecular descriptions of cells undergoing developmental transitions